I have a chinese diesel generator with the yanmar clone engine. I have had trouble with it since the day I got it. The motor starts easily and runs, but it spudders and shakes every few seconds (like a gasoline engine missing a spark every few seconds). It also blows white smoke and sometimes even pops like a small backfire.
I have contacted the seller and they shipped me a new fuel pump, new injector, and new fuel filter.
I installed these parts and it made no difference.
I have changed the fuel 2x with different diesel and checked for other obvious problems.
If I push the governor lever a little, the engine slows RPM and smooths out.
Could a bad head gasket be the issue, or a valve issue?
I have another carrol stream engine (exactly the same) and it runs perfect.
Today I swapped out the shims under the pump...the carrol stream engine has a single thin copper shim and the generator has a single thick one....with the thin shim in the generator, it ran slower and a little smoother, but it would only generate about 100 volts (due to the slower speed)
I know I don't have water in the fuel, and I am starting to think maybe I have something wrong with the oil pressure switch...I will hook a test light to see if the solenoid is keeping power the entire time...the tech guy said I should hook a 12v+ wire to the solenoid to test it while it is running.
I am wondering if anyone has any other suggestions....such as valve clearance, the spacers on the injector, pump shims, etc.
TIA
Jason