Volvo Penta aq130 with 250outdrive

Hy,

I have a boat that i am restoring for about 3 years now, and because my old mercruiser engine was beyond repair, i bought a new (well, when i say new i mean new for me, but older then me ) volvo penta with transmission. I figured out, based on forum posts that my engine is a AQ130C, that should have around 130ps (the old mercruiser had the same).
Now, i know that my transmission is a 250, but i have no idea if it's 250a,b,c ... and can't find how to figure that out.
My boat is a 1989 Regal Medallion 185, 18ft bow rider that is pretty heavy.
And now the problem, the boat just won't plane. I had the engine a full service, and now have excellent compression on all pistons, and the engine runs excellent, but still, the boat just does not plane.
Did some water tests the other day, and with just me in the boat i can go about 21mph, with 2 i can go about 18-19, and with 3 16-17mph. p.s. my tacho is broken, so no idea what RPM...
So, i figured that because the engine + transmission + propeller used to be an a slightly smaller boat i probably have to change the propeller. It took me 4 days and some bent metal to get the old one out until i found an older forum post that sad to use some penetrating oil.. so that did the trick and now i know i have a 14 / 18 propeller.
Where i live, boating is not that popular (we only have a few lakes) and have no shops around that have propellers in stock (btw, my propeller spins counter-clockwise) so i can't test out what to put in, and shipping costs me more then the propeller if i want to return it.

Soooo, after all this long story we can say that i am in a little pickle , and i do need your help.
a. how can i figure out what ratio my trans has?
b. what propeller should i put in? I don't care for speed that much, the lake only has about 10miles, so getting somewhere fast is no issue :rolleyes: but i do want to be able to plane wit 4-5 people on board, and maybe from time to time tow a tube or something.

Any suggestions are more then welcomed !!
Thanks

.........................

Lukas89 said:

Hy,

I have a boat that i am restoring for about 3 years now, and because my old mercruiser engine was beyond repair, i bought a new (well, when i say new i mean new for me, but older then me ) volvo penta with transmission.
When the term "transmission" alone is used, it commonly refers to an Inboard Transmission......... such as the Volvo Penta MS-3 or MS-4.


I figured out, based on forum posts that my engine is a AQ130C, that should have around 130ps (the old mercruiser had the same).
Now, i know that my transmission is a 250, but i have no idea if it's 250a,b,c ... and can't find how to figure that out.
Since you say 250, that would be a stern drive.
The upper gear unit (of the 3 pc stern drive) would be the transmission.
Below that is the Intermediate housing.
Below that is the lower gear unit.

The over-all gear reduction is predicated by the engine, and the change to the reduction occurs in the lower gear unit.
The B unit is a 1.61:1 reduction used behind the V-8 engines.
The C unit is a 1.89:1 reduction used behind the 6 cylinder engines.
The D unit is a 2.15:1 reduction used behind the 4 cylinder engines.

There is no substitute for a correct ratio..... period!
We cannot prop ourselves out of an incorrect redution.... it just doesn't work that way!


You no doubt had to enlarge the transom cut-out for the Volvo Penta AQ series transom shield.
Be sure that you counter-sunk the transom at each of the 6 mounting bolt holes.
The counter-sink is there as to squeeze and compress the 6 FAT O-rings around/against the bolt shanks so that these do not leak water.
The rope-gasket seals within the 6 bolt pattern.

Also note that the 250 Lift-Out unit is for raising the drive only.... it is NOT a power trim device.
If you power up while the drive is NOT locked down, you will damage the lift-out unit.

My boat is a 1989 Regal Medallion 185, 18ft bow rider that is pretty heavy.
And now the problem, the boat just won't plane. I had the engine a full service, and now have excellent compression on all pistons, and the engine runs excellent, but still, the boat just does not plane.
The OHC 4 cylinder engine's ignition distributor is prone to advancing flyweight corrosion and/or rust.
When this occurs, the mechanical advancing system may malfunction, not giving the engine the proper ignition spark lead (aka advance).
If the engine does not see the correct progressive and total spark lead, if will suffer regarding performance and power.

See your OEM service manual for the correct ignition advance curve and verify that your ignition system is delivering it.
If not, that may be part of why it is not performing.


Did some water tests the other day, and with just me in the boat i can go about 21mph, with 2 i can go about 18-19, and with 3 16-17mph. p.s. my tacho is broken, so no idea what RPM...

So, i figured that because the engine + transmission + propeller used to be an a slightly smaller boat i probably have to change the propeller. It took me 4 days and some bent metal to get the old one out until i found an older forum post that sad to use some penetrating oil.. so that did the trick and now i know i have a 14 / 18 propeller.
Replace the tachometer so that you can perform a WOT RPM test.
With the engine in full tune, it must be able to reach the OEM WOT RPM. (see your OEM manual for this info)

Also, the lower unit must be the 2.15:1 reduction for this engine.


Where i live, boating is not that popular (we only have a few lakes) and have no shops around that have propellers in stock (btw, my propeller spins counter-clockwise) so i can't test out what to put in, and shipping costs me more then the propeller if i want to return it.
The only way to properly perform a WOT RPM test is to have the ability to try an array of propellers.

Soooo, after all this long story we can say that i am in a little pickle , and i do need your help.
a. how can i figure out what ratio my trans has?
All 250 transmissions will be of the same reduction.
The lower gear unit is where the final reduction change occurs.
You will need to remove the propeller, remove the ring anode, wire brush the prop shaft bearing carrier as to expose the numbers.
The numbers will be stamped into the carrier housing.
The 2.15:1 ratio will read 2.15 only. In other words, the ":1" will be omitted.

b. what propeller should i put in? I don't care for speed that much, the lake only has about 10miles, so getting somewhere fast is no issue :rolleyes: but i do want to be able to plane wit 4-5 people on board, and maybe from time to time tow a tube or something.
You may need two different pitch/diameter propellers.
One for cruising and one while pulling the tube.

As said, the only correct way to learn which prop is correct for your boat, will be performing the WOT RPM test.
The test must be done with the boat loaded as you intend to use it. In other words..... if you test with no load and use a XX prop, that same XX prop will NOT be correct with a heavier load.

Any suggestions are more then welcomed !!
Thanks

Click to expand...

.

Thank you for your very informative post.

You will have to excuse my lack of knowledge in marine terms, i am a newbie , but fast learner!
And yes, you assume correctly, i did mean stern drive not transmission.


The over-all gear reduction is predicated by the engine, and the change to the reduction occurs in the lower gear unit.
The B unit is a 1.61:1 reduction used behind the V-8 engines.
The C unit is a 1.89:1 reduction used behind the 6 cylinder engines.
The D unit is a 2.15:1 reduction used behind the 4 cylinder engines.

There is no substitute for a correct ratio..... period!
We cannot prop ourselves out of an incorrect redution.... it just doesn't work that way!
So, what you are basically saying is that there is no change counting on boat size, weight or other characteristics, every engine has it's own ratio. Counting on the fact that i did buy the engine + stern drive as a package, and have seen it work ok on the old boat that it was installed on, i am at this point pretty confident that the reduction is not the issue. Never the less, thank you for the indication where the 2.15 is stamped, i will give that a look just to be sure.


You no doubt had to enlarge the transom cut-out for the Volvo Penta AQ series transom shield.
Be sure that you counter-sunk the transom at each of the 6 mounting bolt holes.
The counter-sink is there as to squeeze and compress the 6 FAT O-rings around/against the bolt shanks so that these do not leak water.
The rope-gasket seals within the 6 bolt pattern.

Also note that the 250 Lift-Out unit is for raising the drive only.... it is NOT a power trim device.
If you power up while the drive is NOT locked down, you will damage the lift-out unit.
Yes, you assume correctly, i did have to enlarge the cut-out, but i was very careful with that, and since then the boat has been on the water several times. The swap has been made a year ago, since then i had some cooling problems, some of the cooling system was clogged up and had to make some extensive cleaning. After that i have been for a few test and tune up runs, on the last one (that was the only time that i got the boat to plane, after about 5-10 minutes) one of the valve springs broke. That meant getting all the engine apart, and in that process i did a complete restoration of the cylinder head, and the engine now has very good compression, and is running well.

About the lift-out... let's just say that i found that the hard way, but it's all good now.


The OHC 4 cylinder engine's ignition distributor is prone to advancing flyweight corrosion and/or rust.
When this occurs, the mechanical advancing system may malfunction, not giving the engine the proper ignition spark lead (aka advance).
If the engine does not see the correct progressive and total spark lead, if will suffer regarding performance and power.

See your OEM service manual for the correct ignition advance curve and verify that your ignition system is delivering it.
If not, that may be part of why it is not performing.
I also thought the distributor might need work, and i actually went to the local boat-repair shop and asked them to give that a look. But they said it should be ok, but i am not 100% sure.
Thanks for the heads up, i will give that another look, and consider replacing the rotor if needed.
But, as i said, the engine seems to work very well at this point.


Replace the tachometer so that you can perform a WOT RPM test.
With the engine in full tune, it must be able to reach the OEM WOT RPM. (see your OEM manual for this info)
I know that is a issue that i have to address. I tried to fix the tachometer, and now it seams to respond. My biggest issue at this point is that i don't know from where to get the signal for the rpms. I think it should be from the distributor, but i can't find any connection. Any suggestions?


The only way to properly perform a WOT RPM test is to have the ability to try an array of propellers.

You may need two different pitch/diameter propellers.
One for cruising and one while pulling the tube.

As said, the only correct way to learn which prop is correct for your boat, will be performing the WOT RPM test.
The test must be done with the boat loaded as you intend to use it. In other words..... if you test with no load and use a XX prop, that same XX prop will NOT be correct with a heavier load.
I understand that the ideal situation will be to have the option to try out some propellers, but unfortunately there are no shops in my area that have the propeller that i need in stock, so that means that i have to import one, and the costs of shipping + returning will be almost the cost of the propeller. So, i am doing as much research as i can so that i try to get it right from the first try.
As i said, the one i have now is 14 x 18 L
At this point i am thinking that a 15 X 15 , probably stainless steel is what i want to go for. What do you guys think?
I also thought about a 15x13, but that pitch just might be to low i think.

If i get a good plain with 4-5 people on board and a 30mph top speed, i will consider my self very happy at this point!

Nice job on the quote showing both your questions and my responses. I'll use green font this time!

Lukas89 said:

Thank you for your very informative post.

You will have to excuse my lack of knowledge in marine terms, i am a newbie , but fast learner!
And yes, you assume correctly, i did mean stern drive not transmission.
You will quickly learn the terms!


The over-all gear reduction is predicated by the engine, and the change to the reduction occurs in the lower gear unit.
The B unit is a 1.61:1 reduction used behind the V-8 engines.
The C unit is a 1.89:1 reduction used behind the 6 cylinder engines.
The D unit is a 2.15:1 reduction used behind the 4 cylinder engines.

There is no substitute for a correct ratio..... period!
We cannot prop ourselves out of an incorrect redution.... it just doesn't work that way!
So, what you are basically saying is that there is no change counting on boat size, weight or other characteristics, every engine has it's own ratio.
There are some rather rare cases whereby the hull may dictate a different stern drive reduction.
For example: a very light weight and smaller hull with a higher performance V-8 engine may use the Duo Prop in the 1.78:1 reduction, in lieu of the normal 1.95:1 reduction. However, for the most part, yes...... the engine dictates the final drive reduction!

Counting on the fact that i did buy the engine + stern drive as a package, and have seen it work ok on the old boat that it was installed on, i am at this point pretty confident that the reduction is not the issue. Never the less, thank you for the indication where the 2.15 is stamped, i will give that a look just to be sure.
I have seen several times (over my years of doing AQ series work) where an owner has installed an incorrect lower unit ratio.
They apparently thought that they could prop their way out of this!
Not so!


You no doubt had to enlarge the transom cut-out for the Volvo Penta AQ series transom shield.
Be sure that you counter-sunk the transom at each of the 6 mounting bolt holes.
The counter-sink is there as to squeeze and compress the 6 FAT O-rings around/against the bolt shanks so that these do not leak water.
The rope-gasket seals within the 6 bolt pattern.

Also note that the 250 Lift-Out unit is for raising the drive only.... it is NOT a power trim device.
If you power up while the drive is NOT locked down, you will damage the lift-out unit.
Yes, you assume correctly, i did have to enlarge the cut-out, but i was very careful with that, and since then the boat has been on the water several times. The swap has been made a year ago, since then i had some cooling problems, some of the cooling system was clogged up and had to make some extensive cleaning. After that i have been for a few test and tune up runs, on the last one (that was the only time that i got the boat to plane, after about 5-10 minutes) one of the valve springs broke. That meant getting all the engine apart, and in that process i did a complete restoration of the cylinder head, and the engine now has very good compression, and is running well.
Keep in mind that the water neck fitting is a wear item, and needs to be replaced routinely. In lake/river water you can get about 3 years from one.
Also replace the special beaded gasket underneath it.

About the lift-out... let's just say that i found that the hard way, but it's all good now.
Bummer!


The OHC 4 cylinder engine's ignition distributor is prone to advancing flyweight corrosion and/or rust.
When this occurs, the mechanical advancing system may malfunction, not giving the engine the proper ignition spark lead (aka advance).
If the engine does not see the correct progressive and total spark lead, if will suffer regarding performance and power.

See your OEM service manual for the correct ignition advance curve and verify that your ignition system is delivering it.
If not, that may be part of why it is not performing.
I also thought the distributor might need work, and i actually went to the local boat-repair shop and asked them to give that a look. But they said it should be ok, but i am not 100% sure.
Thanks for the heads up, i will give that another look, and consider replacing the rotor if needed.
But, as i said, the engine seems to work very well at this point.
The OHC 4s have an array of degree markings on the front cover.
With your standard strobe style timing light connected, slowly take the RPM up to 4k and watch the progressive spark advance.
Jot the advance numbers down in graph form.
Compare this to the OEM advance curve.
A lazy advance will prevent the engine from developing it's potential power.

Replace the tachometer so that you can perform a WOT RPM test.
With the engine in full tune, it must be able to reach the OEM WOT RPM. (see your OEM manual for this info)
I know that is a issue that i have to address. I tried to fix the tachometer, and now it seams to respond. My biggest issue at this point is that i don't know from where to get the signal for the rpms. I think it should be from the distributor, but i can't find any connection. Any suggestions?
The tachometer's signal wire will come from the - side of the ignition coil.


The only way to properly perform a WOT RPM test is to have the ability to try an array of propellers.

You may need two different pitch/diameter propellers.
One for cruising and one while pulling the tube.

As said, the only correct way to learn which prop is correct for your boat, will be performing the WOT RPM test.
The test must be done with the boat loaded as you intend to use it. In other words..... if you test with no load and use a XX prop, that same XX prop will NOT be correct with a heavier load.
I understand that the ideal situation will be to have the option to try out some propellers, but unfortunately there are no shops in my area that have the propeller that i need in stock, so that means that i have to import one, and the costs of shipping + returning will be almost the cost of the propeller. So, i am doing as much research as i can so that i try to get it right from the first try.
As i said, the one i have now is 14 x 18 L
At this point i am thinking that a 15 X 15 , probably stainless steel is what i want to go for. What do you guys think?
Give the 15 x 15 a try. Your 250 drive will not allow the use of a 16".

SS props are pretty and are stronger than aluminum props..... but..... you risk prop shaft damage in the event of an impact.
Aluminum will take the hit, typically sparing the shaft.
Also, you should have a spare prop on board.


I also thought about a 15x13, but that pitch just might be to low i think.

If i get a good plain with 4-5 people on board and a 30mph top speed, i will consider my self very happy at this point!
Keep the weight forward. That will help with planing.
Stern heavy hulls have a difficult time getting up on plane.



And while I have your attention..... make sure that you use 30W Engine oil in the stern drive..... NOT 75-95 gear oil.
Heavy gear oil may cause the slinger pump impeller drive pins to become sheared off. If these pins become sheared, you will loose the slinger pump function.

One more thing..... the 250 lower gear unit uses bevel-cut gears.
You may hear the gears whining a bit more than if they were a hypoid cut.

Click to expand...

Is the tach bad or is it the wiring? To check the sender wire while the engine is running short the sending wire to negative the engine should stall. Withe the key on you should have battery voltage at the B+ and B- at the tach.

14x18???? No such prop in the Volvo standard world...

View attachment Volvo_200SeriesProp guide.pdf

You may find this attachment more helpful...

View attachment Volvo Prop.pdf

On it you will see where I initially selected a 15x21 prop for my 260HP 5.7L Merc. My boat, if you are not familiar with vintage Lancers, is a 23 ft cuddy cabin with a 22 degree deadrise deep V hull. Dry weight 4000 lb. I eventually ended up with a 15x17 prop.

Rick, there is a lot of useful information here, that is gold for the newbie volvo penta b20 user

Keep in mind that the water neck fitting is a wear item, and needs to be replaced routinely. In lake/river water you can get about 3 years from one.
Also replace the special beaded gasket underneath it.
I don't exactly understand where this water neck fitting is, so i can't exactly understand what i should change. I will use my boat exclusively in the lake (since the sea is 500miles away from where i live), and the boat does not stay on the water all the time. so not that much wear and tear on it


The tachometer's signal wire will come from the - side of the ignition coil.
I just been to the boat and located what i think is the connection that you mean (i have attached a photo - the red wire, that i point to, is the one that i connected to the tachometer, can you confirm that is the one?). I got it connected with the tachometer, but no change in RPM... so that could mean 2 things: i either got the wire wrong, or my tacho is dead and need a new one.


Give the 15 x 15 a try. Your 250 drive will not allow the use of a 16".

SS props are pretty and are stronger than aluminum props..... but..... you risk prop shaft damage in the event of an impact.
Aluminum will take the hit, typically sparing the shaft.
Also, you should have a spare prop on board.
I asked for a offer at the local shop, as suspected they don't have one in stock, so that will take about 10days to be at my door. I will probably order it tomorrow, and see how it goes. I do use the boat on a lake that has a lot of rocks stones, and the occasional drifting wood, but i am usually careful with this things, so i'm still thinking SS My boat is very stern heavy at the moment, that's why i always ask the passengers to go in the bow of the boat. while that does help in increasing speed, it's not enough at this point.


And while I have your attention..... make sure that you use 30W Engine oil in the stern drive..... NOT 75-95 gear oil.
Heavy gear oil may cause the slinger pump impeller drive pins to become sheared off. If these pins become sheared, you will loose the slinger pump function.
I've just changed the oil in the stern drive. The oil that was recommended, and the shop indicated for my stern drive is: Quick Silver High Performance RM92-858064Q1. So that is what i have at this point.
For sure i will go with the 30w on my next change (since it's also 1/4 of the price of the one i bought ). Or is it indicated to change it now?

kimcrwbr1 said:

Is the tach bad or is it the wiring? To check the sender wire while the engine is running short the sending wire to negative the engine should stall. Withe the key on you should have battery voltage at the B+ and B- at the tach.

Click to expand...

When i bought the boat the tacho was bad. It was blocked at 3000rpm. I got it of and fixed with a friend(or think i did ). Now it does respond (gets the indicator back to 0 when connected to the battery), but i have no idea if it indicates the RPM since i don't have a way of testing it. So it could be both at this point. I will try to get a old tacho from a old car that i have sitting around to see if that works.
I saw the sender wire trick to late to try it when i was there, but i will do that first thing.
To be honest i am trying to not get a new tachometer since that will be totally different then the rest of the dash, but if i don't fix the problem in a few days i will order a new one.

sandkicker said:

14x18???? No such prop in the Volvo standard world...

You may find this attachment more helpful...

View attachment 17952

On it you will see where I initially selected a 15x21 prop for my 260HP 5.7L Merc. My boat, if you are not familiar with vintage Lancers, is a 23 ft cuddy cabin with a 22 degree deadrise deep V hull. Dry weight 4000 lb. I eventually ended up with a 15x17 prop.

Click to expand...

Yes, the size and pitch did seam weird to me also. I have also attached a photo of the prop indication.
Nice chart, but unfortunately my engine has much less horsepower and different ratios, so i can't really use it
According to the internet, my boat is about 2200lbs, and should work fine wit a 130hp engine...

Since i am in photo mode today, i am attaching a photo of the boat also.
Thanks again for all the great help!

Lukas89 said:

I've just changed the oil in the stern drive. The oil that was recommended, and the shop indicated for my stern drive is: Quick Silver High Performance RM92-858064Q1. So that is what i have at this point.
For sure i will go with the 30w on my next change (since it's also 1/4 of the price of the one i bought ). Or is it indicated to change it now?

Click to expand...

That is 90W gear oil and should not be used in your drive. I would change it and replace with 30W.

Do not put that prop back on period unless you can sand it smooth and put a good coat of paint on it. Not worth the trouble just get a 14X17L and see how she performs.

<removed>

My boat is probably similar in size and weight and also has an AQ130C engine. I use a 14x19 when lightly loaded but for larger loads, I put on a 14x17. A 14/15x15 might also work but it may be too little pitch and give you too many WOT RPMs. I also would smooth out and paint the 14x18 if you can and see how the boat performs with it before buying another prop.

.............................

Lukas89 said:

Rick, there is a lot of useful information here, that is gold for the newbie volvo penta b20 user

Keep in mind that the water neck fitting is a wear item, and needs to be replaced routinely. In lake/river water you can get about 3 years from one.
Also replace the special beaded gasket underneath it.
I don't exactly understand where this water neck fitting is, so i can't exactly understand what i should change. I will use my boat exclusively in the lake (since the sea is 500miles away from where i live), and the boat does not stay on the water all the time. so not that much wear and tear on it
The water neck fitting mounts to the upper area (and at center) of the main suspension fork. Remove the transmission for easy access.

Whether the boat stays in the water or not, this part will typically corrode around where the hose connects. You will not be able to see any corrosion until the hose is removed.
This fitting on the suction side of the seawater path. One tiny suction breach (i.e., corrosion), and the seawater pump will not be able to pull in seawater.

FYI.... while this part is actually a "water neck fitting", you will see it called a "hose connector" and even a "thermostat housing"................. and don't ask me why..... I do not know!


The tachometer's signal wire will come from the - side of the ignition coil.
I just been to the boat and located what i think is the connection that you mean (i have attached a photo - the red wire, that i point to, is the one that i connected to the tachometer, can you confirm that is the one?).
No, I cannot confirm from the photo.
Just make sure that it connects to the side with the - symbol..... and not to the side with the + symbol.


Give the 15 x 15 a try. Your 250 drive will not allow the use of a 16".

SS props are pretty and are stronger than aluminum props..... but..... you risk prop shaft damage in the event of an impact.
Aluminum will take the hit, typically sparing the shaft.
Also, you should have a spare prop on board.
I asked for a offer at the local shop, as suspected they don't have one in stock, so that will take about 10 days to be at my door. I will probably order it tomorrow, and see how it goes. I do use the boat on a lake that has a lot of rocks stones, and the occasional drifting wood, but i am usually careful with this things, so i'm still thinking SS.
Your call. Be careful!


My boat is very stern heavy at the moment, that's why i always ask the passengers to go in the bow of the boat. while that does help in increasing speed, it's not enough at this point.
I still suggest that you look at the progressive spark advance with your strobe light.
See if the actual advance curve matches the OEM advance curve graph.
Make sure that the flyweight system and the flyweight "return springs" are able to do two things:
a...... allow the weights to centrifugally create the mechanical advance. (this is an advance that is on top of what you set as BASE advance)
b...... bring the flyweights back in to the zero mechanical advance. (this will bring it back to where you have set BASE advance only)

The engine MUST see the correct progressive and total advance, or it will NOT produce it's potential power!


And while I have your attention..... make sure that you use 30W Engine oil in the stern drive..... NOT 75-95 gear oil.
Heavy gear oil may cause the slinger pump impeller drive pins to become sheared off. If these pins become sheared, you will loose the slinger pump function.
I've just changed the oil in the stern drive. The oil that was recommended, and the shop indicated for my stern drive is: Quick Silver High Performance RM92-858064Q1. So that is what i have at this point.
Quick Silver is a Mercury Marine product.
The Merc guys who work on Volvo Penta stern drives make this mistake quite commonly.
If the slinger pump drive pins becomes damaged due to this gear oil, they should be responsible for the repair.

For sure i will go with the 30w on my next change (since it's also 1/4 of the price of the one i bought ). Or is it indicated to change it now?
Heavy gear oil puts the die cast aluminum slinger pump impeller under a heavy load.
On occasion, the one or two impeller drive pins (some use 1 and some use 2) will become sheared off.
When they become sheared, the large lower unit driven gear no longer spins the impeller.
When it no longer spins this impeller, the slinger pump is no longer able to push the cooler lower unit gear oil up to the upper transmission for cooling.

I would keep the Merc guys at a distance from your Volvo Penta drive!


When i bought the boat the tacho was bad. It was blocked at 3000rpm. I got it of and fixed with a friend(or think i did ). Now it does respond (gets the indicator back to 0 when connected to the battery), but i have no idea if it indicates the RPM since i don't have a way of testing it. So it could be both at this point. I will try to get a old tacho from a old car that i have sitting around to see if that works.
If you try another one, make sure that it is set for 4 cylinders.

Click to expand...

If you are going to do your own tune up work, I'd advise investing in an inexpensive set of diagnostic tools:
timing light ( some come w tachs)
Dwell meter (usually include tach function)
Vacuum gauge.

RE stainless vs aluminum... while later Volvo drives are designed with an intentional weak point in the vertical drive shaft that was designed to break before the gears were trashed, I'd still use a S/S prop with great caution. While replacing a vertical drive shaft is cheaper than a new set of gears, it's still a lot of labor. I consider aluminum props a "load point fuse" A new AL prop much cheaper than a vertical shaft replacement.

Re: OIL...PER am-drew.... that oil is SAE90W Do not run your boat with that lube in it AT ALL!!! A broken slinger pin is difficult to diagnose without dismantling the drive. Perhaps ( and I've never done this... Rick please chime in on this!)
After the proper oil is installed..
1) Put muffs with water flow on drive
2) remove the oil fill plug in the drive
3) REMOVE THE PROP!!!!
4) Start and run the engine.
5) shift into FWD.... see oil splash out of fill plug hole ??????

I may have a used but usable 15x15 short hub prop in my shed somewhere.

So, today I've been out propeller shopping... and the bad news is that no spe******t shops around have a propeller for my 250, so i had to call the guys from the volvo penta dealership, i will have a offer for the propeller for tomorrow, but, i do think it will be quite expensive (around 300-350$ with shipping and all) ... so that's not that good, counting the solas was 170$...
Looking in the volvo propeller catalog i noticed that the 250 and 280 are listed in the same category, that got me searching around an I've found a very interesting topic on the forum (that i can't find right now but have on my work laptop) that with just a little cutting of the line cutter i can fit a aq280 propeller, that seams to be very common and easy to find.
Should i go for it? Is it that straight forward?

Also, did some work today. I got the propeller of, and started looking for the markings of the ratio on the prop shatf bearing carrier... and just as i was going to give up, i found it-> 2.15 as Rick anticipated! So that's one problem out of the way.
Also checked kimcrwbr1 trick, and it did work, when i put the wire on a - the engine stopped. So at this point i am thinking my "repaired" tacho is not that repaired will test out a tacho tomorrow.

And because i got the propeller of, i did some work to it. And while working on it, and seeing the amount of damage it took through the years i decided that i will not go with SS, i think it's to much of a risk, especially on the lake i go on.
But it did manage to get the propeller in a very decent state, and i got all the ugly bumps out, and cleaned really good. I actually really like the new brushed aluminum (see the photos below with the before and after) and i am very curious to see if the repaired version will make a difference

am_dew said:

My boat is probably similar in size and weight and also has an AQ130C engine. I use a 14x19 when lightly loaded but for larger loads, I put on a 14x17. A 14/15x15 might also work but it may be too little pitch and give you too many WOT RPMs. I also would smooth out and paint the 14x18 if you can and see how the boat performs with it before buying another prop.

Click to expand...

I looked for a photo with your boat, and i do think mine is a little heavier, but that info does help a lot, if with the same engine you are running a 14x17, it does help me decide that with just a little more weight the 15x15 should be the one, i will only have to be careful to not over-rev the engine.


@Rick, i will keep in mind your advice and will change the "thermostat housing" after the season ends.


I still suggest that you look at the progressive spark advance with your strobe light.
See if the actual advance curve matches the OEM advance curve graph.
Make sure that the flyweight system and the flyweight "return springs" are able to do two things:
a...... allow the weights to centrifugally create the mechanical advance. (this is an advance that is on top of what you set as BASE advance)
b...... bring the flyweights back in to the zero mechanical advance. (this will bring it back to where you have set BASE advance only)
I do not have the proper tools, and never done this before, but i will ask a friend who has, and will do this as soon as i can get him to come over.

Quick Silver is a Mercury Marine product.
The Merc guys who work on Volvo Penta stern drives make this mistake quite commonly.
If the slinger pump drive pins becomes damaged due to this gear oil, they should be responsible for the repair. Heavy gear oil puts the die cast aluminum slinger pump impeller under a heavy load.
On occasion, the one or two impeller drive pins (some use 1 and some use 2) will become sheared off.
When they become sheared, the large lower unit driven gear no longer spins the impeller.
When it no longer spins this impeller, the slinger pump is no longer able to push the cooler lower unit gear oil up to the upper transmission for cooling.
I would keep the Merc guys at a distance from your Volvo Penta drive!
Yep.. so that was money well spent. I bought on that occasion spark plugs (that did not need changing but i said what the hell) oil filter for the engine (that did not match ) ) and this gear oil .. that obviously is no good
So with all the feedback, now i am worried, and i will probably change the oil as soon as i get a chance, not in winter as i first thought...
As i said, i am glad i can find useful information here, because i can't rely on the information i find locally. Boating is not that popular here, not being close to the ocean / sea and we are just a few guys that own boats, so it's hard to find people that know what they are doing, and i don't want to go 500miles for a oil change....



@sandkicker
I always enjoy buying new big-boy toys, even dough i don't spend that much time working on mechanical stuff (i am a automotive mechanical engineer as a profession, but i don't work in the field only as a hobby) so will surly consider buying them!

Regarding the AL propeller, as stated earlier, working on my propeller made exactly the point you stated, so i will go for AL.
I will do the oil change as soon as possible. And i guess the 5 steps are to check if the pump is ok?

A propeller will be much welcomed, but the problem is that i am from the other side of the pond, in Europe, so shipping may be a issue.

OK, so got the quote for the propeller today from the volvo dealer: 470$ ... and i found a solas short hub for a 280aq with 167. so that is a huge difference.

The thread that i was talking about on the forum is this one:
http://www.marineengine.com/boat-forum/showthread.php?425805-propeller-help-AQ280

where the link with this solution is listed: http://tinyurl.com/o9j4sfu
so it looks a no-brainer, just a little cutting the line cutter and i can get 3 propellers for the cost of one original one.

I can't see any drawbacks on the long term, so i think i will order the solas one

That price include the hub kit?

Yes, it's all included, just get it and fit it.
I ended up buying one that is more expensive, but has way faster shipping, should be here in about 1 week. I do hope it will be ok.

Meanwhile, i was trying to determine how fast could i go with the boat with a 15 pitch. I did found that max rpm is around 5100, but what should be the slip on a boat my size? 15-20%?

You have no choice but to install the new propeller and then perform a WOT RPM test.
If the engine is able to reach the OEM WOT RPM and not exceed that by very much, you will likely be OK.
Conversely, if the engine is NOT able to reach the OEM WOT RPM, then you may have one of several issues:
...the prop is too aggressive.
...the final reduction is incorrect.
...the engine is not in full tune.
...the engine is tired.


.

ok, so i managed to get a working tacho (cost me 3$ from an old car ) and went for a short run on the lake:

https://www.youtube.com/watch?v=xMLEAtgxI2U

So, with the freshly fixed,old propeller, with only me in it i went 24mph at 4000rpm.
Very curious to see how the boat performs with the new 15x15 that should be here next week.

concerning your thoughts Rick, i do hope it's the prop to aggressive part

also, next week i will do the oil change in the stern drive, as suggested, and also, i hope, the fine tuning of the spark advance.


meanwhile, today while on the lake, i was thinking of building a hydraulic trim for the boat. Shouldn't be hard to get a hold of a electric hydraulic pump from some kind of and old tractor/machinery, and the pistons are a easy find. Has anyone done this?

The new prop should get you close to 4800rpm by my estimate. Adjust the points with a dwell meter first then check adjust base timing to spec. You should see a huge improvement in the hole shot as well.

meanwhile, today while on the lake, i was thinking of building a hydraulic trim for the boat. Shouldn't be hard to get a hold of a electric hydraulic pump from some kind of and old tractor/machinery, and the pistons are a easy find. Has anyone done this?

Click to expand...

You will spend more time engineering this, building it,and then working out the issues than you will if you were to just simply purchase a “C” or later Volvo Penta drive.



.

Lukas89 said:

ok, so i managed to get a working tacho (cost me 3$ from an old car ) and went for a short run on the lake:

https://www.youtube.com/watch?v=xMLEAtgxI2U

So, with the freshly fixed,old propeller, with only me in it i went 24mph at 4000rpm.
Very curious to see how the boat performs with the new 15x15 that should be here next week.

Click to expand...

Looking and sounding good! I am sure the 15x15 prop will make a huge difference in getting you must closer to max WOT RPMs and the hole shot.

Ok, quick update from the lake... installed the 15x15 solas prop... now i can only go 3000rpm... i can't understand...
And also is very hard to go right, and very easy to go left.... ?! ....

............

Lukas89 said:

Ok, quick update from the lake... installed the 15x15 solas prop... now i can only go 3000rpm... i can't understand...

OK.... see my post # 19 again.
What you have effectively done during the lake run, was the WOT RPM test.
A few things to know:
..... if the engine is healthy and is in full tune, DO NOT..... repeat.... DO NOT continue operating this boat under these conditions. You will Over-Burden this engine at any RPM!
..... the WOT RPM test is performed in order to find out if the final reduction and/or propeller diameter and pitch are correct for the engine.
..... the rule that one pitch change equals a 200 or 300 RPM reduction or increase is an estimate ONLY. It is not written in stone.



And also is very hard to go right, and very easy to go left.... ?!
You are experiencing "steer torque" .... aka "prop wash steer torque"
Each time that we change a propeller to one with a different diameter and pitch, the trim fin/torque tab must be adjusted as to counter any "steer torque".
This correction will not be effective at all RPM.
Choose the adjustment that helps eliminate most steer torque at the RPM or Hull Speed that you prefer while up on plane.
If the current position causes a pull to Starboard, then move the trim fin/torque tab towards Starboard.
If the current position causes a pull to Port, then move the trim fin/torque tab towards Port.

NOTE: the trim fin/torque tab on the 250, 270, 275 has a small surface area. This style trim fin/torque tab is rather inefficient at correcting steer torque. You'll need to get it close and live with it!

Click to expand...

There is not mutch i can do here. I will try removing the hydrofoyl to see if there is any difference, and also another trim setting, and change back to the old prop.
But I must say I really don't understand why with a smaller pitch(18 to 15) I can go less rpm (From 4000rpm to 3500now)... it really is beyond my understanding. Could it be the bigger diameter? From 14 to 15?
At this point I am really considering selling this boat... after 3 years of work I would really want to enjoy a decent run on the lake.

Ok. So it's back do the drawing board.

Please excuse my last frustrated posts but i did put all of my eggs in the new propeller basket, and when that did not turn out ok it was a big hit for me.. and for the first time, in 3 years of working on this boat i did consider selling it

But i won't give up without a fight, I'm not asking for much, just to be able to go on plane, and reach 25-28mph with 3-4 people on board would be ok for me.
So, going back to Rick's post as a start:

1.the prop is too aggressive.
what i know: with the 14x18 i can go 4000rpm and 23mph. (only me on the boat)
with the new solas 15x15 (i actually found somewhere that it's 15.5x15) i can go about 18mph at 3300rpm. Both with only me in the boat, adding people only makes it worse. That is very strange for me, and i can't really understand why. I've tried all the 3 positions for the stern drive (the settings for the trim i mean), and I've also tried it with or with ought the hydrofoil that i have installed. It did not make much of a difference.
Why this is i really can't understand. Could it be the difference in diameter? (14 to 15.5 ? )
Should i return the 15x15? i only have about 2 weeks to do that. Is there any point in keeping it?
p.s. i installed the 14x18 back at the end, just to make sure that nothing changed with the engine, and had similar results as before.

2. the final reduction is incorrect.
I've checked, and the reduction is 2.15, as it should. Going down to 1.8 or anything else i think would make it worse?


3. the engine is not in full tune.
The carburetors have been cleaned and set up to factory settings.
The spark advance, has not yet been tuned professionally. My bad. But i did try different small tuning on the lake, and is now at the best possible setting i can find. Ok, i agree a fine tuning is needed, but that could not make a huge difference. Maybe i could go from 23 to 25mph, but it can't do miracles.
Is there anything else i can tune?

4. the engine is tired.
It's an old engine. That could always be a issue. As stated in my previous post i invested quite a bit in the engine, and now i have decent compression on all cylinders (between 11-12), workshop manual says 12-14.
what else could be in bad shape? end what could i address?
Could i have a bad distributor maybe?

5. The engine is not fit for the boat.
As mentioned, this is not the original engine. My boat came with a 130hp mercruiser that was beyond repair. I have bought this volvo penta + sterndrive that i thought is similar with the mercruiser. The papers that it came with say that it has 95.5 kw (almost 130hp) and all the clues lead me to believe the engine is a volvo penta aq130 (dual solex carbs, and the shape fits - see the photo).
When installing it i made sure the cavitation plate is just a little bit above the bottom of the boat.
The internet says that my boat has 2200lbs (1000kg), could i just be under-powered, and maybe whatever i do this engine will not be able to push the boat at a decent speed?

6. Anything else?
I am thinking maybe the boat could have water somewhere in a hidden place that is making it to heavy. I'm thinking of finding some way to measure how heavy she is.
Is there some kind of a hidden gem that i can't see and destroys all the balance?
Is there anything i'm missing that anyone can think of?


And the final question here, on the drawing board is... 7. should i just quit? Sell the boat at whatever price i can get for it, and get another one in good working order? I really don't want to do this, after 3 years of working on it, but sometimes you just need to say it's enough.

I can see why you are frustrated! I am not an expert by any stretch on props, but I do not think the difference between 14 and 15 inch diameter would be all that great. If anything, any difference would be offset more by the reduction in pitch. Is the new prop stamped as being 15x15? Do the fins on it appear to be angled less than those on your 14x18? I'm just pondering if perhaps you got the wrong prop than what you ordered?

That was one of my first thoughts (and hopes to bo honest) ) also, but the stamping on the propeller checks out 8712-150-15 ....
I really can't understand why that big difference in pitch does not help...

..................

Lukas89 said:

Ok. So it's back do the drawing board.

Please excuse my last frustrated posts but i did put all of my eggs in the new propeller basket, and when that did not turn out ok it was a big hit for me.. and for the first time, in 3 years of working on this boat i did consider selling it

But i won't give up without a fight, I'm not asking for much, just to be able to go on plane, and reach 25-28mph with 3-4 people on board would be ok for me.
So, going back to Rick's post as a start:

1.the prop is too aggressive.
what i know: with the 14x18 i can go 4000rpm and 23mph. (only me on the boat)
with the new solas 15x15 (i actually found somewhere that it's 15.5x15) i can go about 18mph at 3300rpm. Both with only me in the boat, adding people only makes it worse. That is very strange for me, and i can't really understand why. I've tried all the 3 positions for the stern drive (the settings for the trim i mean), and I've also tried it with or with ought the hydrofoil that i have installed. It did not make much of a difference.
Why this is i really can't understand. Could it be the difference in diameter? (14 to 15.5 ? )
Should i return the 15x15? i only have about 2 weeks to do that. Is there any point in keeping it?
p.s. i installed the 14x18 back at the end, just to make sure that nothing changed with the engine, and had similar results as before.
What is the OEM specified WOT RPM for this 4 cylinder push rod engine?

2. the final reduction is incorrect.
I've checked, and the reduction is 2.15, as it should. Going down to 1.8 or anything else i think would make it worse?
2.15:1 is correct for the 4 cylinder engine.


3. the engine is not in full tune.
The carburetors have been cleaned and set up to factory settings.
The spark advance, has not yet been tuned professionally. My bad. But i did try different small tuning on the lake, and is now at the best possible setting i can find. Ok, i agree a fine tuning is needed, but that could not make a huge difference. Maybe i could go from 23 to 25mph, but it can't do miracles.
Is there anything else i can tune?
That is Incorrect! Ignition timing is critical. Look up your OEM ignition advance curve and make dang sure that your ignition system is delivering it as per the specs!


4. the engine is tired.
It's an old engine. That could always be a issue. As stated in my previous post i invested quite a bit in the engine, and now i have decent compression on all cylinders (between 11-12), workshop manual says 12-14.
what else could be in bad shape? end what could i address?
Could i have a bad distributor maybe?
Yes.... very possibly. You will not and cannot know until you roll your sleeves up and check it throughout the RPM range.

5. The engine is not fit for the boat.
As mentioned, this is not the original engine. My boat came with a 130hp mercruiser that was beyond repair. I have bought this volvo penta + sterndrive that i thought is similar with the mercruiser. The papers that it came with say that it has 95.5 kw (almost 130hp) and all the clues lead me to believe the engine is a volvo penta aq130 (dual solex carbs, and the shape fits - see the photo).
When installing it i made sure the cavitation plate is just a little bit above the bottom of the boat.
The internet says that my boat has 2200lbs (1000kg), could i just be under-powered, and maybe whatever i do this engine will not be able to push the boat at a decent speed?
Possibly. You have chosen the older Volvo Penta 4 cylinder push rod engine. These are not powerful engines.
You would have done better had you chosen one of the Volvo Penta OHC 4 cylinder engines.

6. Anything else?
I am thinking maybe the boat could have water somewhere in a hidden place that is making it to heavy. I'm thinking of finding some way to measure how heavy she is.
Is there some kind of a hidden gem that i can't see and destroys all the balance?
Is there anything i'm missing that anyone can think of?


And the final question here, on the drawing board is...
7. should i just quit? Sell the boat at whatever price i can get for it, and get another one in good working order? I really don't want to do this, after 3 years of working on it, but sometimes you just need to say it's enough.
Well...... you certainly know by now that boats are NOT investments, they are always expenses. We just simply use it up as family fun, enjoyment and entertainment.
You may as well continue and give it one last shot.
Get your tachometer working, or replace it. It is an important instrument.
Be sure to check the ignition advance at idle, at 1,000RPM, 1,500RPM, 2,000RPM, 2,500RPM and right on up to the RPM at which it quits advancing.
Compare this to your OEM advance curve.




FYI..... that plastic in-line fuel filter is illegal as installed within an enclosed engine bay. That can get you a nice citation.

Click to expand...

.