Was given an abandoned Honda GX160 on a Davey water pump. After a general fiddling around it starts easily but only runs for a few seconds then cuts out. Doesn't matter what I do with the throttle, can rev it to the max or let it idle, it just cuts out. Will start up again and do the same thing, runs perfectly but just for a few seconds.
Have been through the carb a dozen times, cleaned out the fuel tank, fuel flows to carb perfectly, carb bowl fills at a decent level, float and needle are perfect, main jet and all carb passages clean, have tried with muffler off thinking it might be blocked by mud wasps, checked the valve clearances, tried several good spark plugs. It is like there's a timer which only allows it to run for a limited time. All the automatic throttle levers move correctly when the motor starts, all the springs are perfect.
Decided it might be the coil or the capacitor or some chafed wiring so took off the side cover to get to the electricals. In doing so had to tip it on it's side to get to the lower screws. Some very thin liquid came out of the valve cover vent. I had checked the oil level visually before doing anything, could see it was full, exactly up to the filler hole threads.
Drained the sump and what came out looked to be fuel mixed with just a tiny bit of oil. Noted there's a yellow wire coming out of what might be a sensor in the crankcase which goes to a little square metal case which is probably the capacitor. Would this be an oil pressure sensor which cuts the ignition if the pressure is too low because the "lubricant" is too thin ??
Yes, could put some proper oil into the sump and reassemble everything but thought should ask the experts before wasting more time and effort.
