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onan 2500 lp generator

babies
Explorer
Explorer
I have a onan 2500 lp generator that has 20 hrs run time and it won't start. Determined thru a lot of testing that I have spark but no fuel. I was reading on a previous post that this type of generator will experience this problem if the vent line is clogged. I have looked for this vent line in the lower left of the generator and can't find it. Does this 2018 model not have that vent line or am I just to ignorant to find it?
6 REPLIES 6

mellow
Explorer
Explorer
When I first got mine I had an issue with the flex propane lines kinking in the propane closet when I would push them back in (I have 2) and not letting enough propane get to the generator (other stuff would work fine), it would just turn over and would run if I sprayed it. I also had issues with the air intake filter being dirty, it would do the same and blowing it out and cleaning it fixed that issue. These things require A LOT of propane and need air.
2002 F-350 7.3 Lariat 4x4 DRW ZF6
2008 Lance 1191 - 220w of solar - Bring on the sun!

babies
Explorer
Explorer
The generator hasn't been started for at least 12 months. I have gas to all my appliances so the blockage of fuel is at the generator. I applied starter fluid and it fired up but only ran for a moment before it starved itself of fuel.

So I'm pretty sure the blockage is at the LP pressure regulator OR at the carb as some of you have suggested. Has any one removed an LP carb before and do you have any suggestions if you did?

vern_kelly
Explorer
Explorer
Make sure the battery is fully charged. I've had that problem twice where mine refused to start even though it cranked the generator over. After taking the plug out and checking for spark and putting it back in (no easy job) and trying multiple times to no avail. I suspect the spark was weak during cranking.

After charging the battery for several hours it started right up. Another thing is to check the plug gap as there is a difference between the gas model and the propane model. The gap is less on the propane model. I try to run mine every 6 weeks or so after charging the battery when in storage. Run your stove burners first before the generator.

A clogged carb could cause the same problem but propane carbs are not as prone to this as gas models. Doesn't mean it could not happen. Test all gas appliances water heater, heater. Oil level check also.

Good luck!
1998 2500 Dodge V10 3.55 Quad cab. Lance 5000 camper 9'10" and tow 17.5 ft Larson Boat

bgum
Explorer
Explorer
Try a puff of starting fluid.

gvgeode
Explorer
Explorer
If it turns out you do have propane flow and it still won't start it may be your carburetor. How long has it been since you last ran the generator? From unhappy personal experience, it's important to run the generator, with load preferably, at least every few months to avoid problems of it eventually not starting.
2010 F-450, 6.4PSD, CC, DRW, 4X4, 60 gal fuel tank
2009 Lance 1055

jimh406
Explorer III
Explorer III
Mine is much older. Did you prime it? Also, are you sure the propane is on? You might try to light the stove to make sure you have propane.

'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.

NRA Life Member, CCA Life Member