Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Onan generator no spark. I have this generator out of a motorhome in my shop with no spark. I was asked by the owner to tune it up. when it first came in it would start and run just fine. So I changed the spark plug, fuel filter, cleaned air filter, changed the oil. I ran the generator for 5 minutes, and noticed some residual oil dripping off the bottom. I used brake clean and compressed air to clean out the bottom of the generator. I went to start it and it started and ran. shut it off, then tried to restart and it started and ran a few seconds then shut off. would not restart. I asked the customer again about the generator, and she stated that this is what happened to her. ( she forgot to mention it to beforeI started on it.) I removed the plug and no spark. checked the signal wire to the coil and it has 5.63 v ( A/C scale ) while cranking. Checked primary coil resistance (.8 ohms) checked secondary coil resistance ( 1.111k ohms) I do not have any service information on this unit! Am I checking the ignition out correctly or am I missing something? I do not see a low oil switch on the engine, is there one hidden somewhere? Can you provide a wire diagram and specs on the ignition test that I have done? I feel the coil has failed. Is there a place online that I can get parts without going to a cummins /onan dealer? Thank you in advance Hal.
I have found a service manual in pdf form online that has the coil specifications.primary .5 @75 deg F and 1.100 for the secondary. This manual also shows a low oil switch inside the engine. I have also read online that the oil level switch was discontinued on later models due to failure rate.
I would still like an opinion as to if this model has one, and if you think it may be at fault here. I am going to test the mag per the manual tomorrow.
Thanks Hank. Thats what I suspected after I found the specs in the manual. I just wanted a second opinion to make sure . Since I was only getting 5.6 VAC during cranking I had a feeling it was too low. Now I know for sure.
Whats involved in getting to the Magneto on this unit, ( how much time, so I can estimate it to my cust) ?