General Discussion

Hello,

I had some luck with a partial rebuild I did a couple years ago on the starboard engine. I replaced one bad piston (right rear) that got pitted/corroded from water entering in from a plugged riser most likely. The engine was frozen when I took it over 6 years ago ('72 410 Commander). Long story short, I've only put in around 50 hours since finishing the rebuild. I had the heads machined, a couple of bent valves replaced, new pushrods, the intake boiled out, and the risers changed. The engine seemed to run fairly well but it has lower oil pressure at idle after it warms. 65 lbs when started, but then drops down to the first mark on the original gauge (assuming the gauge is accurate). I've was in denial of course and just tried to keep more RPMs on it. I don't run the boat as much as I should. I have used Sea Foam but not religiously. Last weekend I started it up and it was smoking and blowing oil out the exhaust into the water. It's a gray smoke, not steam. I also found residual oil in the same right rear cylinder. I've yet to do a compression test and haven't torn into anything yet but I'm wondering what I might have done. I've checked the PVC valve. I'm considering spraying a can of seafoam into the carburetor while it's running but that will make more of a mess. I'm also wondering if the oil pump got plugged up, or it's failing or I messed it up somehow, or anything else when I was inside it and if the low oil pressure has ruined something. I never saw it get hot anywhere. The engine fires up and runs, that's the good news. Before I go deeper to look at valves, guides, seats or the crossover chamber, try and do a manual test of the oil pump, look for shavings, etc., I was hoping I could get some guidance from some of you experts. Maybe you can talk me out of my slump.

The engines seem to have lower hours on them according to those that felt the cylinder linings, that's why I only replaced the one piston. It didn't smoke like this or blow oil out into the water until now. It has sat for a few months since I started it last. I did have an old school mechanic that helped for the important stuff during the partial rebuild but he has since disappeared off the face of the earth. The boat's in San Rafael, CA.

Thanks for any help.

Regards,

Jeff Bentley

"Risky Business"