Yanmar 2GM20 suddenly smokes and quits???

[Cheechako]

Could definitely be a fouled injector nozzle.
Could be worse... piston crack.
A push rod could have popped off the rocker, easy to see with rocker cover off.

[Wotname]

Originally Posted by Cheechako

Could definitely be a fouled injector nozzle.
Could be worse... piston crack.
A push rod could have popped off the rocker, easy to see with rocker cover off.

Yes, a reasonable possibility. I once saw this almost happen on a near new 2GM20 (less than 50 hrs).

Took the rocker cover off to re-torque the head bolts and found the nuts holding down the rocker arm assembly very very loose to the extent the valves were not fully opening. I estimated it was only hours (or minutes) from quitting.

Proves the point that all new engines should be carefully checked after the first couple of hours.

[Cheechako]

I had it happen on a Perkins. Still a mystery if the rocker popped off on startup as a result of some minor water ingress to the aft cylinder overnight, or as a result of the fouled injector tip. But the fouled injector had to be rebuilt even after we got the push rod back in place. We made a better/higher riser at the same time just in case....

[Sailorman Ed]

Sorry to take long in reply. Spoke to several mechanics, finally removed the exhaust elbow (in was in quite good shape) and the last mechanic said replace both fuel filters despite having fuel come out the loss need injector nuts. it was the small seconadary filter on the engine, clogged just enough to prevent it from running. Of course this was after arriving at Cape Canaveral and coming within 2 feet of crashing into the Christie McCaulif bridge when they had trouble getting one span to open and the wing pushing us into it.
Thanks again for all the suggestions. Back in New Bern, NC.

[Wotname]

Thanks for the update Sailorman Ed. It's always good to hear about how the problems are resolved.

I must say it was a surprise to hear that it was the engine filter as they rarely give much trouble provided the primary filters are replaced regularly. When was the last time you replaced this secondary filter?

And I bet you are changing it on the other engine as well