Generator Shutdown

BRIDGESRE · 10-09-2009, 09:10 AM

I have a problem with generator shutdown on my 1997 B190. On very hot days my genset shuts off after about 1 hour.When it shuts off the fuel line at the carburetor has no gas present. Has anyone ever heard of these units vapor locking,and if so how did you solve the problem? The unit has had a new fuel pump installed.This is not an immediate shutdown, it stumbles a short time with air bubbles in fuel line before it stops.
This is an Onan Microlite 2800. Thanks for any help.

cooperhawk · 10-09-2009, 09:42 AM

Check to see if a fuel line is routed near the exhaust or any other hot source.

345bill · 10-09-2009, 09:44 AM

I agree with you that it appears to be starving for fuel. I'm not familiar with your set-up but I can give you some food for thought and explain the fuel system delivery on my 345 MH in case it might help.
My Onan gets fuel from same tank the MH uses, however the pick-up tube only goes about 1/2 way down inside with the intent that you can't run your tank dry while using the gen out in the boonies.

Also,on mine, the fuel pump 12V is tied in to the oil pressure switch so in event of loss of oil pressure, or even low oil, the 12V feed is cut off to the pump.

Hope this helps. Let us know what you find.

Mikethefixit · 10-09-2009, 11:32 AM

I don't have first hand knowledge of MH's but I recently ran into this problem with a yard tractor and have seen it many times on various gasoline engines.
What I found was a VENT problem. The vent in the fuel cap was plugged and causing the unit to pull the fuel tank into a vacuum,when all the air is evacuated from the tank,fuel will cease to flow.
Just a thought.
Roger

bryanl · 10-09-2009, 05:11 PM

Make sure it was installed properly. On my '91 190, the exhaust cut out was off by 2" so the airflow through the genset was restricted. In addition, the genset fuel feed was just tapped into the main engine line so genset fuel was pulled through the tank fuel pump. The fuel feed is supposed to have its own tank draw.

Another Microlite I have in an Overlander has problems like you describe. I haven't got after it but an initial inspection indicates that insulation batting is coming loose and blocking airflow near the intake vent. I've got to pull it and make sure that the air path is clear.

Also, check for the winter/summer flap just behind the air filter towards the top. It selects whether to use fresh or 'preheated' air. There is a wire handle outside the plenum to control the flap.