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OMG 3.0 doesn´t run fine

P

Peter.deleu

New member
I have a OMG Cobra 3.0 in the boat. The engine starts fine an can run on idle for more then 30 min.
When I run the engine on 3000 rpm for a while, there is smoke or damp coming out of the pipe that goes into the air filter.
It looks like water damp, but I’m not sure. And also the motor starts running less smooth.
After a while, the engine stops running. When I try to start, it cranks slow. To slow to start.
The water temp looks OK,
When the engine is cold again, it cranks and starts normal.
What could be the problem?
 
I think that there’sa cooling issue. When the engine runs, a lot of water is coming out the sterndrive. That looks fine.
But how do I check if the cooling water is cooling the engine?
Is there a waterpump on the engine? Is the water from the engine running through the engine, or is there a heat exchanger?
The problem is that I can’t find a manual or drawings
 
I can't tell you what is there or what isn't as I can't see it.

If the temperature gauge indicates normal, then the cooling system is likely to be ok (the water is flowing where it should be and at an adequate quantity).

If there is no water in the cylinders, I would a fuel supply problem as the engine runs for a while. I would make sure the fuel tank vent is open first. If that is ok, then I would change the anti-syphon valve. If that doesn't resolve it, I'd suggest you need to do more troubleshooting.

Does the voltmeter indicate adequate charging by the alternator?
 
It sounds like blow-back from the cylinders making its way to the valves. On my Ford 302, the blow-back was evident by air and oil blowing out of the oil fill. It would idle well, but over about 1500 rpm it would shut down. I checked with two mechanics that said it was probably time for an overhaul. I did get an overhaul, and a similar starting problem was solved by a new Arco PMGR starter, after going through two other standard old-style marine starters.
NOTE: I am not an expert but have some experience. I got my main advice from the experts on this website, who have infinitely more experience than I. There may be other tests that can be done.
 
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