New Member here from Western Australia. Great thread and I have spent several hours reading through this thread. Picked up a great deal of information and wish to thank active members for the effort to educate others.
My interest is with a problem I am experiencing with a Yanmar
L48 driving a fire fighting pump.
Motor starts and splutters away with blue/black exhaust but won’t run up to speed. I have given it a shot of WD40 into the intake with the air cleaner removed and it will run up to speed.
Maintenance background Oil changed, oil strainer cleaned ( no noticeable debris) fuel filter replaced, new fuel line, Fresh fuel, valve clearances set to 005”
After motor had run up to speed added fuel injection cleaner and ran at full load for ~10 hours hoping to clean/burn up any carbon deposits. Under load motor runs sweet Unfortunately Problem still persists on start up. ( it’s like the choke stuck on with a gas engine).
I have checked external governors springs and levers etc which seem free.
I did have a problem with damage to the fuel pump with the stop solenoid having been dislodged from the pump body which I replaced the small “O” ring and Used cold weld to bond to pump casting.
I plan to double check that the pump has been inserted properly into the fork linkage and double check air is bleed from the system and absolutely no leaks.
Any suggestions on what to check next?