Volvo penta set up 5 years... starting for 1st time

[RandyJ]

I've gone over this engine pretty well. Squirted oil in cylinders, turned it over a whole bunch of times then checked compression... 70-40-50-50... did it all over again with another fresh dose of oil...and kept doing it till I got 140-120-50-100. Obviously there is a stuck ring... Any tips on getting this compression up before I put the spark plugs back in and try to fire it up? I'm really babying this motor to keep from causing damage...I really want this one to be right. Should I just go ahead & start it then check compression again after it warms up a little?

 

[freelunch]

Re: Volvo penta set up 5 years... starting for 1st time

Well what that would suggest to me, and I'm just using my basic knowledge of piston construction here as a guide, is that the oil you are dumping into the cylinder with a 50 psi reading is slipping right past your top compression rings and then right on by your lower oil control ring as well. That great a variance between cylinders I'm sure you know is not anywhere near allowable tolerances. Just speaking for myself I would pull the block and drop your pistons and inspect whats causing the problem. Replace your rings all around and hopefully you don't have some scoring in the suspect cylinder walls as well.

 

[freelunch]

Re: Volvo penta set up 5 years... starting for 1st time

Oh and also if your dry compression test readings are as low as 40 and have a 30 psi difference between your high and low readings it would seem like that bottom end is shot anyway so a overhaul would be inevitable.

 

[Don S]

Re: Volvo penta set up 5 years... starting for 1st time

Start it up and run it for a while, then do a compression test.

 

[freelunch]

Re: Volvo penta set up 5 years... starting for 1st time

hes already at 40 psi on a dry test, what good would that do?

 

[Don S]

Re: Volvo penta set up 5 years... starting for 1st time

hes already at 40 psi on a dry test, what good would that do?

The engine hasn't run for 5 years. Rings stick, running it and warming it up usually frees things up that are just stuck from non use.

 

[RandyJ]

Re: Volvo penta set up 5 years... starting for 1st time

Yep Don...that's kinda my theory. Steel and aluminum have different expansion coefficients so a little heat & vibration from running should get the rings to moving unless they're stuck really tight. I guessed that there might be a little junk growing on the walls of the cylinders with open valves. I'm thinking that getting it cranked will smooth out the walls and the heat and oil will give the rings a decent shot at breaking loose from corrosion. I don't have new plugs to put in at this time but I did use a wire brush on the plugs, cleaned the points with emery cloth and got good firing at the coil wire. All I could get the engine to do is backfire and pop a few times. I figure the oil is probably fouling the plugs but will help seal the rings. Will try to pick up new plugs tomorrow and pray that the timing is right...if so, it should start with new plugs. The carb fuel pump was a bit crusty & passage from bowl to pump was cruded up. I couldn't get the pump to squirt gas into the carb throat so I've been using starting fluid. Looks like I'll have to put a kit in the carb. I don't see a fuel filter anywhere on this boat and am using an outboard tank to get her going.
I was just hoping you guys might know of some additive or something I can pour/spray down the carb with the motor running that might help loosen the rings & clean the cylinder walls. I recall several years ago that pouring water down a carb on running engine is supposed to clean pistons or something like that...don't know for sure if it's a good thing or bad. I've done that before on a bad running engine and about all it did was make it run worse. The low compression might be valve seats skunked up a bit... hoping that running it will let the valves bop around and seal better then maybe bring up the compression on the low cylinders. Surely the gas & air movement will blow out anything that might be keeping valves from closing all the way. If I can get it to run I'll do an oil change right away. The oil in the motor looks like new clean oil....a very good sign.

 

[Tail_Gunner]

Re: Volvo penta set up 5 years... starting for 1st time

Well you could fill the jug's with tranny oil for a week or so, that loosen her up toooo............8)

If you ever try such a thing make sure you drain the oil and thourghly spin her up before putting the plug's back in.....:}

 

[RandyJ]

Re: Volvo penta set up 5 years... starting for 1st time

GOOD NEWS!!! Still couldn't get anything going last night. The starter relay is bad so I'm using a jumper wire to crank it. I cleaned out the carb & put a kit in it last night. Not much trash and no corrosion. The top gasket was badly warped as was the fuel pump diaphragm. At first it wouldn't do anything but backfire when I tried to start it. I took out the distributor hold down bolt to turn the distributor a little further then it hit and purred like a kitten... sounds like a very good motor.

 

[bruceb58]

Re: Volvo penta set up 5 years... starting for 1st time

Make sure you time it correctly with a timing light.

 

[RandyJ]

Re: Volvo penta set up 5 years... starting for 1st time

But of course Sir. 10 deg. BTDC according to my book.