12 kw Onan

[piii]

I have a 12 kw Onan generator 1983 vintage that ran off on me due to diesel mixing with the oil in the crankcase. The diaphram in the fuel lift pump ruptured and allowed the diesel to enter the crank case. I suspect the pistons/rings picked up the oil/diesel mixture and added fuel causing the run away. I changed the lift pump, changed the oil and filter and verified I had fuel to the injectors. The engine starts, makes noise and is smoking. It also isn't running smothly. Any thoughts as to what direction I should proceed?

[Avenger]

If it was mine I'd be looking to do a compression test to verify the health of the engine. Anything could have happened there, bent valves, wiped out rings, or it could be something simple like a bad injector and residual fuel in the exhaust.

Short of a compression test, try loosening injector lines one at a time and see if you can isolate the problems to any cylinder.

[SeaEric]

I think there's still a 1983 vintage RTO 15kw available for cheap from another forum member. Let me know if you want it and I can connect you.

[Canuck Dennis]

Also check voltage output prior to putting it on line, damage may also have happened in the electrical end

[piii]

Thanks for your help. Doesn't look promising as I suspected! Any other thoughts would be appreciated.