yanmar 2gm that won't idle?

[Dan Geltmacher]

I can't get my 2gm to idle below 1000 to 1100 rpms. I know this can't be right. I pulled the exhust elbow and cleaned it out, it wasn't as bad as I thought it would be. Also to start it I must place the throttle all the way foward. We it starts I get lots of gray smoke. After I throttling down to 1500 rpms I get a small amount of gray smoke. Appreciate any advice.Dan

 

[SCHAEFER]

FUEL

WHEN HAVING TROUBLE WITH MY 2 GM I STARTED WITH THE FUEL...PUMPED OUT TANK CLEANED TANK NEW FILTERS ETC....UNLIKE YOUR CASE THOUGH IT WAS MY EXHAUST ELBOW THAT WAS CLOGGED.....HOWEVER STILL START BY MAKING SURE YOU ARE GETTING GOOD CLEAN FUEL...SCHAEFER

 

[Don Riha]

Simple thought

I assume that you verified that the throttle linkage is not sticky and not allowing it to back off fully. Sounds like it is getting too much fuel. Gray smoke could be valves, too much oil, bad fuel, etc.

 

[Jay Hill]

Try the linkage

After years of vibration, the actual linkage at the motor end may be out of adjustment. Of course, I'd still check the fuel system.

 

[Kevin]

2GM20

I too get some gray smoke at start up but it reduces to bassically zero when the engine is fully warm. Assuming that you do not have linkage problems with the cable and your elbow and fuel are ok, I would take a look at the throttle set srew which is located on the left side of the motor. When I first got my boat it's idle was about 1000 rpms and I reduced to the factor spec of 750 by use of the idle set screw. Loosen the lock nut and turn the screw counter clockwise to reduces the idle, be sure the engine is warm before setting the idel speed.

 

[Dan Geltmacher]

what now?

Thanks for all the advise. I changed the two filters that I could find, fuel water separater and secondary and they were dirty. The fuel water (rancor) was so foul I couldn't drain it at first. I removed it and cleaned it out good. Molasses like sludge in the bottom. Question, if that first filter was that bad, I'm wondering what my fuel tank looks like, and what to do about it? Happy new year! Hawaii Dan Illusians

 

[joe]

same problem

Just went through the very same problem. I finally talked with yanmar distributor and gave the problem to the yard mechanic. yanmar suggested the governor linkage--two springs that act to control flow--these proved ok. the mechanic adjusted the idle at the pump inside the high prssure side which appears to fix it. scary to get a stall headed into tight quarters. good luck