Logo
FULL SITE MENU

AQ131A No power in gear

M

mohavepc

New member
Hello All:
I have a 19' Bayliner Capri with a Volvo Penta AQ131A. It ran great last season then we winterized it in November (we have long seasons) we took it out in Feburary and put in the water. Fresh gas and it fired on the first crank as always. went to back it off the trailer and it sputtered and died. we have been fighting with it ever since. we hav changed the following. Timing belt ( broke 2 teeth), Fuel pump (had less than a pound of pressure), Accelerator pump, (fuel sputtered under throttle throw), checked timing under idle (was spot on) 6-7 degrees at 4000 rpm without load. I can't understand what could have changed so quickly that would cause this. We had the outdrive checked and it got high marks except for a slight play on the prop shaft that the shop said was well within reason and to fix it would require a full pull down bit the outdrive was not binding in any way. we had the prop tuned at winterizing but the shop we took it to has triple checked that aspect.
any help would be appriciated.
 
At 4000 RPM the timing should be 32º-36º BTDC whether you have load on the engine or not. It also should be 6º BTDC at 900 RPM.
 
Sorry about that typo it was supposed to be 36-37 at 4000 and six at idle. I guess wht Im trying to figure out is what would cause a sudden diffrence.
 
In my experience, major problems are usually due to one and only one main factor. You may have some minor contributing factors, but it is the main factor the one you have to look for.

Since you have replaced the timing belt, I would make sure the belt was installed correctly; that is, the gears were where they should be. Check this link as a reference.

http://www.threefattigers.com/Protocore/Volvo/TimingMarks.htm

Once yo are 150% sure that the timing belt was installed correctly, then you can look at other possibilities (faulty new fuel pump or stuck anti-syphon valve in the fuel tank?).
 
I will triple check the belt later this week when I go get the boat. Would debris in the antisyphon valve cause a sudden loss of power like that? I had planned on looking at the anti Syphon valve as soon as I can.
 
Actually, the compression readings you have posted are quite low. They should be 142-170 psi according to the VP Operator's Manual. Low compression readings could be caused by worn piston rings, but also by an incorrectly installed timing belt.

A stuck anti-syphon valve would cause an obstruction in the fuel suction line. Symptoms would be low fuel pressure and insufficient fuel delivered to the carb. This could also be caused by a clogged fuel filter on the suction line, or by a closed/clogged shut-off valve if you have one installed.
 
Last edited:
Off topic.... but I have to poke a little fun at the thread title.
How is the power in neutral? :D


On a serious note......., Mr. El P is your man..... take heed of his advice. :)
 
autospares03 said:
Click above to see the (link removed) do the Top Gear Power Lap For the past few years, the Top Gear Power Lap has been one of the standards by which we judge the world's fastest supercars. The Stig has piloted everything from the Ascari A10 to the Pagani ...
Click to expand...
I've read several of your recent posts. It appears that you are attempting to use this venue for advertising purposes primarily. :rolleyes: This is a marine related forum.... please stay in context, or frequent the automotive forums!

.
 
Last edited:
RicardoMarine said:
I've read several of your recent posts. It appears that you are attempting to use this venue for advertising purposes primarily. :rolleyes: This is a marine related forum.... please stay in context, or frequent the automotive forums!

.
Click to expand...


I'm Sorry?:confused: but this is the only post I have made on this forum. I started this thread after joining and I have not tried to advertise anything. I'm not sure to what you are refering. If there is a problem with my post please inform me so I may correct it.
Thank you
 
el_pescador said:
Actually, the compression readings you have posted are quite low. They should be 142-170 psi according to the VP Operator's Manual. Low compression readings could be caused by worn piston rings, but also by an incorrectly installed timing belt.

A stuck anti-syphon valve would cause an obstruction in the fuel suction line. Symptoms would be low fuel pressure and insufficient fuel delivered to the carb. This could also be caused by a clogged fuel filter on the suction line, or by a closed/clogged shut-off valve if you have one installed.
Click to expand...

I will be checking the belt out tomarrow. I got the boat home tonight. I will let you know what I find if anything. The timing belt I put 1 in another volvo penta a couple years ago and I looked at this one after they put it in and it still didn't run right but I'll try again. I appreciate the advice and the help.
Thank you:)
 
mohavepc said:
I'm Sorry?:confused: but this is the only post I have made on this forum. I started this thread after joining and I have not tried to advertise anything. I'm not sure to what you are refering. If there is a problem with my post please inform me so I may correct it.
Thank you
Click to expand...


Mohavepc, Ricardo's comments are not addressed to you but to someone with the username autospares03. Read the quote in Ricardo's post, who was originally made by that individual and later was deleted.
__________________
 
mohavepc said:
I will be checking the belt out tomarrow. I got the boat home tonight. I will let you know what I find if anything. The timing belt I put 1 in another volvo penta a couple years ago and I looked at this one after they put it in and it still didn't run right but I'll try again. I appreciate the advice and the help.
Thank you:)
Click to expand...

You are welcome. It may take some time, but you'll find the problem. And by then, you will know your boat much better.:)
 
el_pescador said:
You are welcome. It may take some time, but you'll find the problem. And by then, you will know your boat much better.:)
Click to expand...

I am (or was) an Auto Mech for 28 years. Electrical specialty but good at general diagnosis too. this one has me stumped. I know I should be able to figure it out but truthfully it seems as soon as you add water to the mix it seems to through me off. I realize the Compression was low but I guess I was trying to say that There was compression and that it was not the issue. there is no smoke so I doubt rings. I am thinking an issue with the valvetrain though. I'm not looking forward to tearing into that part as I had hoped to have this beast back in the water for memorial day. ses la vie I supposed.
Thanks again
 
We have a running boat again. It seems that the High speed jet on the top of the carb has come loose. Tightened it and we are back on the water. I did double check the belt as suggested and it was right on. I need to replace the seawater impeller because its running a touch too hot. I am at 200-205 degrees when it used to run at 175. the system is tight and not sucking air and I am sure the shop more than likely ran it dry a few times so I will pick that up tomarrow. Thank you all for the help and I will peek in from time to time.
Stay Wet :^)>
 
Well it has been a little over a month since I started this thread and we have yet to have a good day of boating out of this volvo pos. It is now overheating on plane but nott at idle. we have replaces the sea water impeller, the fresh water knocke on the outdrive along with the hose. we have checked flow on the outdrive, checked flow on the exaust manifold. I am at a point of putting it up for sale and looking for a jet boat with a chevy small block. I really don't understand why this has been so difficult. 3 shops, 6 mechanics and still no answers.
I appriciate the help those here have offered and hope others have better luck with the tempermental and often failing volvo line. I have seen so many threads here and on quite a few other forums about the overheat problem. they all seem to point to the flange on the outdrive. oh and we also have replace the waterpump and checked the heat exchanger which is clean and fairly new (within 1 1\2 years) so as you can imagine i have pretty much had my fill of bayliners and volvo penta.
Thanks for you time all and for letting me vent.
be safe out there
 
Back
Top