Help on Volvo Penta AQ125a Inboard

[Pacificid]

I have a 1984 Bayliner capri with a Volvo Penta AQ125a engine 280 outdrive, In has set since last september and was covered and left in storage outside, it ran welkl last time we fired it. this season when uncovering it we noticed am excessive amount of mositure was inside and inside the engine compartment, when we tried to fire it up we noticed that a fuel water mixture was blowing out thru the top of the Carb, we resrach the caarb made sure everything was connected and then drained the fuel completely and refuled, we attemted to resart and the same thing happened again. In further examping the engine we check the oil stick for signs of water in the Oil, it was good, we check the sparkplug and ignigtion system and notices that when we pulled the 1 and numbert 4 cyl plugs a clar liquid was in the sparkplug seat, we tooka syring and sucked out several table spoins of this liquid that appeard to be water. we then took a airhose dried all the sparkplug seats and repalce the plugs with new ones and attemted to start again and the process is repeated. what else shouod we be looking at, I suspect maybe stuck valves not sure and if so dio we have to dioa complete rebuild on the head or what?

Mitch

 

[Robj]

Re: Help on Volvo Penta AQ125a Inboard

You got water in the cylinders either from a cracked block, head or bad manifold. The water is getting into the cylinders and then through a bad intake valves getting pushed up through the carb. You can do a compression test, but the findings will be obvious, bad valves. You need to most likely start thinking of a rebuild, or new motor and check you manifold to ensure it is OK. Better yet you can get an automotive engine and marinize it. It will be cheaper than getting yours rebuilt, but at least with a rebuilt you know what you are getting.

Good luck and have a great day,

Rob.

 

[slia67]

Re: Help on Volvo Penta AQ125a Inboard

The Volvo 125 is an OHC (over-head cam)engine, so the likelyhood of a sticking valve is very unlikely.

I didn't understand about the watery substance coming from #1 &4 cyl. Was it from the sparkplug seat or from the cylinder itself?

Have you checked the tension on the timing belt? It may be that you have jumped timing and are pushing compressed fuel/air mixture back through the carb.

Did you do the winterizing, or did someone else do it?


Doug

 

[Pacificid]

Re: Help on Volvo Penta AQ125a Inboard

Hi Doug Thanks for yor reply. The water substance that you spoke of came from inside the sparkplug seat it, self, since I have dried it I have also since then taken off the distributoir cap to notice some rust inside, I am going to replace the cap, Points ad the condenser. I did check the sparkplg wire and they all seem ok Then perhps I will check the timing. I have never done the timing on this engine so assume its the same as any other engine is that correct. Also I check the Oil pretty well no signs of water in the oil, so I dont beleive it a crack block or anything. So then the next step would be to doa compression check? shold I remove the Valve cover asw well at this point and look at the inside?

Mitch

 

[slia67]

Re: Help on Volvo Penta AQ125a Inboard

Since there was rust in the dist cap. I would make sure the the mechanical advance on the dist is functioning freely too. (but that shouldn't keep you from starting and giving you the popping thru the carb, although it will effect performance)

The first thing I would do is check the tension on the timing belt. There should be very little deflection, as it uses a spring loaded self tensioner pulley. You should be able to get at it easily. If you are keeping the boat and suspect it has not been changed, I would definitely change it. I think mine was less than $50 and was good insurance against a break down while miles away from my launch. It was also less than a two hour job if I remember correctly, and that includes reading the instructions that came with the belt about 8-10 times to make sure I was reading it correctly. If you are having a hard time finding one, go to a good parts store and I believe a Volvo automotive 2.1 engine has the same belt. I had them cross reference a Doug Russell part number.

You can try a compression test, but if the belt has jumped timing the readings will be way off target.

Hope this helps.


Doug

 

[slia67]

Re: Help on Volvo Penta AQ125a Inboard

Mitch,

The water could be condensation from normal heating and cooling as long as it is confined to the outside of the engine and the engine compartment. Most people try to get as much ventilation as possible without compromising your winterization efforts. Could this be the cause?


Doug