run problem with Onan Marquis 5000 BGM
fuel pump approx 6months old - tested pumping good fuel filter NOT clogged - it is passing fuel, yes enough fuel yes it has enough oil it will start , run a few seconds quit im thinking stuck/...
Forum Discussion
The early BGM's without electronic governor used a N.O. OP switch.
Later versions used a N.C. OP switch.
On later models, when you energize starter and oil pressure builds up, the governor controller will move throttle rod at carb. to full fuel.
then will stabilize at 1800 rpm when engine starts.
Make sure throttle rod has not become disengaged from actuator (other end of rod from carb).
The "thunk" sound could be many things, It is common for carbon build-up on top of piston and in cyl heads to cause a knocking noise as engine turns over. only fix is to remove heads and clean carbon from heads and pistons. This is actually an ONAN recommended maintenance procedure.
Later versions used a N.C. OP switch.
On later models, when you energize starter and oil pressure builds up, the governor controller will move throttle rod at carb. to full fuel.
then will stabilize at 1800 rpm when engine starts.
Make sure throttle rod has not become disengaged from actuator (other end of rod from carb).
The "thunk" sound could be many things, It is common for carbon build-up on top of piston and in cyl heads to cause a knocking noise as engine turns over. only fix is to remove heads and clean carbon from heads and pistons. This is actually an ONAN recommended maintenance procedure.
