Onan Genset 6.5 Cranks Slowly, Won't Start, Issue Solved!

[zaa]

Hello all,


I thought I'd share my story, to maybe help someone in the future. The Onan Genset 6.5 in our 1986 Elandan began cranking very slowly. I did the obvious things, checking grounds, making sure all the connections were clean and solid. I checked for fuel and spark, and I replaced the battery.


This morning, I was thinking through how it all works, and realized that the generator produces AC power even while cranking, and that a short circuit in the AC side could be causing drag. I pulled apart some AC connections, and sure enough, I found a ground wire that had come loose, and fallen against the hot side terminal.


I repaired that, and it cranks and starts no problem


I'm so glad I found that, I was dreaming of how I'd get that monster generator out.


Later,
Z

[M & J]

 

[Schwarzkopf9]

I think this helps me . I just got the 4.0 BFA in my winne going (needed new muffler, pipe, resonator...). It ran for about 45 minutes(perfectly, running ac) until it shut off(fuel maybe?). went to restart and it cranks slowly. Now Im thinking its because I left the ac unit in the "on, ac" position. Ill check it tonight...

[Rickf1985]

I find that hard to believe because you are not generating anything near usable power until the rpm is up at least 1000 rpm and rated power of 110 volt at 60hz. at 1800 RPM. Cranking is is at most 150 rpm. And the voltage regulator is not going to kick in until it starts anyway. I think the loose ground wire you found is the key, that is telling me that there is a chassis ground still not making contact somewhere and it is using the AC ground as the DC ground to start.

[tmsnyder]

Does it have circuit breakers on the generator?  easy enough to test out that theory, turn them off and try cranking.   I'd bet more on corrosion in the starter circuit terminals though.

I think this helps me . I just got the 4.0 BFA in my winne going (needed new muffler, pipe, resonator...). It ran for about 45 minutes(perfectly, running ac) until it shut off(fuel maybe?). went to restart and it cranks slowly. Now Im thinking its because I left the ac unit in the "on, ac" position. Ill check it tonight...