generator driving me nuts. always well maintained, but now having issues. flash code not helping me. replaced fuel and filters and added seafoam to the tank. it will run for 10 minutes, sometimes up to 1 hour with smooth idle and then just shut off. it seems like something is getting hot and opening a contact. it will not start back up for about 15 minutes and then same thing. I don't think its a fuel pump or carb issue. seems more like coil or internal short. can anyone help me please. p.s. bought Honda 2000 backup genny for now seemed like cheaper fix.

Post the dataplate model and serial number (or model and spec code at least). It's very hard to give you much info without knowing which Onan 5.5 KW you have.For most models, this will tell you if it's the coil - disconnect a plug wire, connect a spare plug, touch the plug base to the engine and press the start button, then release it. It should spark at least once. If it's sparking multiple times, then it's a gas or air problem. If it sparks only once, when you release the start button, the coil is working and it's something else. If no spark (for most Onans), it's the coil. To be sure, measure voltage at the coil. If you get 12V on then off and no spark, it's definitely the coil.

Onan has problems with fuel pumps getting hot and shutting down. Had the same problem last week. Would run for 30 seconds to no longer than an hour. Replaced with low pressure generic fuel pump from napa for $50 and problem solved.

I had a 6.5 NHD Onan that would shut down after a while. It turned out to be a cracked solder joint on the control board.

thanks drycamper11 themode number is 5.5hgjab-5900d spec d, I cannot even locate the coil. is it internal? its definetly a split crowd, most of my friends say fuel pump or carb, I ruling out carb, just thought I would throw this at the experts before opening up wallet, thanks for your help.

serial number is lo60001990 then a bunch of other numbers- specd c186-2 5.5 hgjab-60 hgjab.... options r086-2 a223-1 c162-2 thanks

onan 5500 generator problems | Good Sam Community

2wheelglider
Explorer
Nov 08, 2013
Onan has problems with fuel pumps getting hot and shutting down. Had the same problem last week. Would run for 30 seconds to no longer than an hour. Replaced with low pressure generic fuel pump from napa for $50 and problem solved.
DryCamper11
Explorer
Nov 08, 2013
Post the dataplate model and serial number (or model and spec code at least). It's very hard to give you much info without knowing which Onan 5.5 KW you have.

For most models, this will tell you if it's the coil - disconnect a plug wire, connect a spare plug, touch the plug base to the engine and press the start button, then release it. It should spark at least once. If it's sparking multiple times, then it's a gas or air problem. If it sparks only once, when you release the start button, the coil is working and it's something else.

If no spark (for most Onans), it's the coil. To be sure, measure voltage at the coil. If you get 12V on then off and no spark, it's definitely the coil.

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