Onan LP 3600 Generator - Hard Start

Roadrunner,

Thanks.

Maybe coincidence that starting was improved.

I will look for the vent hose you describe.

There's some possible mixup between the crankcase breather and gas regulator vent hoses here. The part (on mine, anyway) that says "Onan OHV", right on the front of the engine, is the valve cover. The hose that attaches to the top of it is the crankcase breather hose which is routed back to the air intake so any vented crankcase vapors go back through the carburetor. Debris in that hose would cause a problem, but there shouldn't be any. The lpg regulator is on top of the engine, more toward the back than the front. It has 3 hoses going to it: Gas in, gas out, and vent. According to the installation instructions the vent hose is to be routed so "it vents to the outside", whatever that means. On my installation, the vent hose exits the left (air intake) side of the generator and is covered with a foam sock squished between the generator case and a mounting support. It's this hose, if it has an open end, that gets clogged up by critters.

mine did not like to be low on oil. If slightly off level it was hard starting if level was down. Don't forget you tested oil stopped and as soon as you turn it over the level changes. Fill it to full and I'll bet it works better. You did say it read 1/2 full right?

Of course, remove the cover of the gen set.

Roughly in the center of the unit you will see a metal box about 3" X 3" (the propane regulator, I think). Mine has the legend embossed on it "Onan OHV". In the upper left corner you will see the tube attached to this box. I loosened the plastic hose clamp with pliers and just pulled off the tube.

I couldn't reach the other end of this tube, even with my needle nose pliers so I just tapped the tube with the pliers and some debris popped out.

Viola! That did it.

Joe

Hey Joe - where is this vent tube located? Rather know ahead of time in case I ever experience this issue! ST

SOLVED!

After other fixes didn't work (topped off oil level), I went online and Googled "Onan LP Generator - Hard Start".

A poster said a common hard start problem is caused by a clogged vent tube (about 1/2" outer diameter rubber hose - mine was cream colored).

I pulled off the easy to reach end and tapped the hose a few times. Some dirt seemed to come out.

Result - now works!

Thanks to all who had responded.

Joe