Outdrive

"I have a 1999 Bayliner Capri

"I have a 1999 Bayliner Capri 2050SS w/ 5.0 Mercruiser.

Today while cruising at slow speeds (10-20 mph) the engine RPMs would surge up and down slightly.

Also, at higher speeds (45-50mph) it was running at 5,000+ RPMs which I know is not normal. There was no wind or any extra weight in the boat from the norm.

After I got it home on the trailer, I put it in gear (both Forward & Reverse), and was able to turn the prop (and shaft) freely by hand with a popping sound. I wasn't able to turn the prop the opposite direction of what ever gear that it was in at the time.

I was hoping that it was going to be a spun prop hub, but what possibly could be the issue.

I get the feeling that I'm looking at a pretty expensive bill???

Thanks in advance for your replies.

Steve"

"Steve:

Your test of the pr

"Steve:

Your test of the prop in gear was normal. The following site is Mercruiser's bulletins. You can go there and look for your problem. For anyone here to help you, more info. is needed on your engine; i.e., carb. size or EFI, recent repairs performed and anything else you can describe about your surging and high RPM problem. What is the condition of the prop? New, dinged, chips in it, chunks missing.

http://www.boatfix.com/bulletins.htm"

"Thanks for the reply.

It&#

"Thanks for the reply.

It's a carbureted engine with a recently replaced starter.

As far as I know, the prop is the stocker with only a small ding on the O.D. of the hub.

I bought the boat used in April of this year, so I don't have a lot of info on what's been done in the past. I've had it out ~12 times this summer. I haven't put a whole lot of WOT time on it. Just some tube/ski pulling and running it to spots where the kids can swim.

Today when idling in neutral, the RPMs were smooth as always. When I engaged it Forward and increased to a steady 1/4 throttle, it would rev up and back to the set RPMs, back up...etc. It would only rev, at most, about 500 RPMs or so. I'm not sure because I wasn't watching the tach at the time. That's when many bad thoughts start going through your mind about what's getting ready to break down.

When I would take off 1/2 - 3/4 throttle and trimming up, the RPMs were very high for the relatively "slow" speed. As compared to previous trips under the same conditions.

It;s like something's slipping somewhere or not completely engaging.

Could it possibly be the prop hub, or something more serious based on my limited ability to describe what's going on.

Thanks,

Steve"

"Steve.

When a prop hub sta

"Steve.

When a prop hub starts to slip, (if it doesnt let go all together,) you will normaly be able to get drive power up to a certain rev, say for example 2500, over that the engine will continue to rev effortlessly but the boat may even slow down as the prop slips on the hub and you loose drive power.

If it is slipping like this you can normally bring the revs down somewhere below the slip point and the prop will grab again.
If you feel this is the type of thing that is happening it may be time for a bit of work on the old prop.
If you pull off the prop sometimes you can see marks on the hub where it has slipped, if you have any friends with a prop the same they may let you borrow theirs to put on your boat for a run just to confirm that the prop is the problem.

Cheers
Peter C"

"Steve:

Peter is telling yo

"Steve:

Peter is telling you like it is from eons of experience. If it is an aluminum prop, they are inexpensive to just replace vs. repair but check the repair cost anyway. If it is a stainless steel prop--get it fixed.

Do you have a spare prop? You need one; if the cost to repair it is justified, have it done. You can get a cheap plastic limp home temp. prop or a decent aluminum prop that would save the day. I have a stainless, aluminum and a plastic backup. I use the aluminum prop if I am in shallow waters I am not familiar with.

Since you pull skiers and tubers, consider a four blade aluminum (low cost and repair) prop. It will launch your boat like a rocket to pull the skiers up. Hope we helped."

"I put it in gear again, and w

"I put it in gear again, and was not able to get the prop to spin inside the hub. The shaft turned with it.

I appreciate all the responses so far.

Since it may not be a prop issue based on the shaft tuning with the prop, is it possible that it could be the converter or something else?"

"Steve

I would suggest to y

"Steve

I would suggest to you that when you put your engine in gear and try and turn the prop by hand that while ever my backside points towards the ground you will never be able to replicate the force created on your prop by in excess of 200 horsepower pushing against water.

The only way you would be able to move the prop by hand is if your hub had totaly colapsed and as your symptoms dont fit the bill for a total colapse you are just going to have to take our advice.
If we are understanding properly the symptoms you have described, ""IT IS THE PROP"".

Cheers
Peter C"

"Steve,

90 percent sure you

"Steve,

90 percent sure you have a spun hub on the prop. You simply can't always tell from the relationship between the shaft and the prop for some reason. You also won't be able to spin it by hand. I've been there. If it is stainless, there might be a 4 sided nylon hub insert that can be replaced. ~$25.

The only alternative is a spun engine coupler and they let go all at once and don't slip like a hub. Take it off and see if has a replacement hub (look for hairline cracks - thats all it takes). If the hub is not replacable, see above. The Rev. Guy and the Rev. Pete from the Church of Boats will not steer you wrong! Good luck!

Hays"

Praise the Lord Mista Hays !!

Praise the Lord Mista Hays !!

Rev Peter.

"Steve

Just a closing note,

"Steve

Just a closing note, before I pulled my boat out for its winter service, my port drive was doing almost the same as you described, but it would breakaway at around 2700 revs and yes the prop hub has failed but seen they want an arm and a leg for a prop in the land of Ozz I will be getting it repaired before I wet its bum again.

Cheers
Peter C"

"I'll take it off and see

"I'll take it off and see what's up.

Thanks for all of your input, everyone!!! This is an awesome message board for quick, educated and civil responses. I can't say so much for the message boards for my other hobbies (i.e. ATVs, etc)



Steve"

""This is an awesome messa

""This is an awesome message board for quick, educated and civil responses. I can't say so much for the message boards for my other hobbies"

That's because these folks don't play those boards."

I hit some rocks in shallow wa

I hit some rocks in shallow water at the lake at low speeds and it damaged my prop and bent the prop shaft. I took the prop off and took off the shaft bearing carrier retainer ring and now I can't get the shaft to slide out. It is a mercruiser alpha 1 gen 1 outdrive. How does is come out?

"Timothy

If you havent got

"Timothy

If you havent got one by now, its time you purchased a manual before you go any further and have a good read, or you are going to end up costing yourself a lot more money before you are finished.

Free tip as well, dont hijack someone elses posting, if you have a problem you need some help with, you need to post a new topic so all the members can see it and offer their help other than just the people who have been dealing with Steve's problem.

You can purchase a manual from the sponsors of this site or they are regularly available through Ebay.

Cheers
Peter C"

"Just an update:

A new prop

"Just an update:

A new prop hub kit was installed, and it made no difference.

I took it out yesterday with the same results as before.

At about 3,000 RPMs, the engine surges up and down. Like possibly a carb problem or fuel filter issue???

Also, at 51 mph, the tach was showing over 6,000 RPMs. Which I think is impossible to do without the engine scattering all over the back of the boat.

The needle on the tach went over the 6k mark at about 49-50 mph. The water wasn't real smooth, or it ususally hits about 54 mph.

So the problem is.... engine surging at 3k RPMs, and too high of RPMs on top end.

I didn't notice any smell of burnt rubber from the coupler after a run.

When I first bought the boat, running at 54 mph, the tach would be around 4900-5100 RPM.

It seems that the speed is staying consistance, but the RPMs are going up gradually. One day it was 5100, then up to 5400, then 5800, now over 6000.

Is this a bad tach or an engine about to let go?


Thanks,

Steve"

Steve
Check the connections a

Steve
Check the connections at the back of the tacho and all you connections down at the coil.
if all is OK it is most likely the tacho.

Sounds like you may have a carby issue or the tacho problem is affecting the coils performance.

Cheers
Peter C

"So possibly the carb, tach, o

"So possibly the carb, tach, or coil.

Is a bad ICM capable of doing this as well?"

"Steve

dissconect your tac

"Steve

dissconect your tacho wire at the negitive side of the coil and try it, that will disscount the tacho as being the route of the problem.

If your ICM was breaking down it can cause problems, but as far as your engine doing 6,000rpm the only way it would do that is if there was no load at all on the engine and believe me you would know it was doing it by the noise it was making.

See if you can borow a hand held tacho that you can use to compare the revs to your tacho as you go along.

So if your prop is OK and your tacho was in fact right, your drive coupling is probably stuffed.

Cheers
Peter C"

"I've ordered parts to rep

"I've ordered parts to replace the coil, ignition sensor, distributor cap and rotor, wires and plugs, and fuel/water separator filter.

I'll start there since they probably need replaced for tune up purposes anyway.

Thanks for the responses.

Steve"