Forum Discussion

Explorer

Sep 25, 2013

Cummins Onan 5500 question

Hi all, I have a new toy hauler with a Cummins Onan 5500 generator model HGJAB built in. When operating with a load it runs really nice and smooth but when at idle with little load it throttles up and down every 3-5 seconds. Sounds like it may want to stall but then surges back up over and over again. I took the front cover off and you could see the carburetor gassing it like I said every 3-5 seconds. Also, the exhaust smells kinda gassey like it's running rich. Does this sound like normal operation? It's new and only has 102 hours on it.

Thanks for your time

24 Replies

Kpackpackkelley
Explorer II
Sep 26, 2013
They made those carbs were you can't adjust them. Now if you want to pull that plastic piece for the altitude off the the carb then you can adjust the main jet I did not tell to do it. Is it still under warranty ? If you do try to adjust it mark where you started. What's the spec on your gen I will look for a service manual so you can read about setting the sensitivity .
JSS1439
Explorer
Sep 26, 2013
Bump

Anybody else know if this would be abnormal operation or does it sound right.

Thanks for your time.
JSS1439
Explorer
Sep 25, 2013
harold1946 wrote:
First thng I would check it the altitude setting and then electrical connection at the choke for loosness or corosion.

Thanks Harold, I checked all that and the connections look good and the altitude setting is on 0. I live in Ohio which is not a high altitude so I assume that is correct.
harold1946
Explorer
Sep 25, 2013
First thng I would check it the altitude setting and then electrical connection at the choke for loosness or corosion.