OMC Cobra 2.3l Hot Starting Problem

[buffyporson]

My 1989 OMC 2.3 is extreamly difficult to start after a long high speed run. It starts easily cold and if it is immediately re-started after a run, but will not start if it is left to cool for between 10 mins and 2 hrs. Cranks fine. Runs great the rest of the time. Plugs are getting spark, carb is getting gas (accelerator pump - pumps gas). I have replaced plugs, points, condensor and coil. Leads are fairly new. Coil is getting a full 12V while cranking. Compression is 95psi on all 4 pots.
Someone suggested it could be vapor lock but as the accelerator pump squirts gas not vapor I don't think it could be. Also even after 1-2hrs of cooling off it still wont start. Leave it another couple of hours and it starts fine. One thing I noticed is that there is a fair amount of water (condensation ?) in the intake manifold after a run.
Any suggestions welcome.

 

[wifisher]

Re: OMC Cobra 2.3l Hot Starting Problem

If you can see water in the intake manifold, I think you have a problem. Pressure test the cooling system. I would guess an intake manifold or head is cracked, or a bad gasket.

 

[buffyporson]

Re: OMC Cobra 2.3l Hot Starting Problem

Thanks for the suggestion. I can see water droplets in the manifold if I shine a flashlight down through the carb venturi. Not sure if this is just condensation (cool gas/warm manifold) or a cooling leak.

 

[Don S]

Re: OMC Cobra 2.3l Hot Starting Problem

Compression is 95psi on all 4 pots

You should be seeing 165 compression, 95 is way to low for easy starting.
I would try another gauge first and verify that is what the compression really is.

 

[buffyporson]

Re: OMC Cobra 2.3l Hot Starting Problem

I thought 95psi was a bit low too. Same on all cylinders though, and the engine runs great. Doesn't burn oil, no water in the oil. I'll check my compression gauge.