Onan 4000 ky no start

tonym · 10-06-2017, 11:20 AM

Don't know where to look next. This unit is about 10 yrs old total hours unknown. It has good fuel and flow ,spark and compression. Carb was gone through completely . New spark plug also. Does the control module tell the engine to start? It does appear to be a timing issues since it makes a "puffin" sound while cranking and cycling. If so can the problem be with the module? Thank you.

Hacksaw · 10-06-2017, 02:23 PM

I once had similar trouble with my 4000. When I was away from my trailer it ran out of fuel. After that it would start and run only while on cranking mode. Put in a new board to fix it. I'm guessing it didn't like the high and low rpm surging as it starved for fuel and fryed something.

tonym · 10-06-2017, 02:31 PM

Thanks, Hacksaw
Is there any way to check module?

Hacksaw · 10-06-2017, 02:52 PM

I'm sure there is but looks tricky to me. I'd bet most trouble shooters swap out the board with a good one rather than go through it. Those Onan gens have several "fail safe" circuits that run through that board.

Hacksaw · 10-06-2017, 03:05 PM

Hey Tonym: Remembered switching boards on mine and no difference. Just dug out copy of receipt for the repair and turns out I was mistaken. My fix was the voltage regulator, not the board. $149.00 in 2008. Sorry to aide in your confusion.

tonym · 10-07-2017, 10:54 AM

Thanks, Hacksaw Ill check it .

10-06-2017, 11:20 AM	#1
tonym Junior Member Join Date: Oct 2017 Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Onan 4000 ky no start Don't know where to look next. This unit is about 10 yrs old total hours unknown. It has good fuel and flow ,spark and compression. Carb was gone through completely . New spark plug also. Does the control module tell the engine to start? It does appear to be a timing issues since it makes a "puffin" sound while cranking and cycling. If so can the problem be with the module? Thank you.

10-06-2017, 02:23 PM	#2
Hacksaw Senior Member Join Date: Sep 2016 Posts: 881 Likes: 206 Liked 309 Times in 173 Posts	Re: Onan 4000 ky no start I once had similar trouble with my 4000. When I was away from my trailer it ran out of fuel. After that it would start and run only while on cranking mode. Put in a new board to fix it. I'm guessing it didn't like the high and low rpm surging as it starved for fuel and fryed something.

10-06-2017, 02:31 PM	#3
tonym Junior Member Join Date: Oct 2017 Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: Onan 4000 ky no start Thanks, Hacksaw Is there any way to check module?

10-06-2017, 02:52 PM	#4
Hacksaw Senior Member Join Date: Sep 2016 Posts: 881 Likes: 206 Liked 309 Times in 173 Posts	Re: Onan 4000 ky no start I'm sure there is but looks tricky to me. I'd bet most trouble shooters swap out the board with a good one rather than go through it. Those Onan gens have several "fail safe" circuits that run through that board.

10-06-2017, 03:05 PM	#5
Hacksaw Senior Member Join Date: Sep 2016 Posts: 881 Likes: 206 Liked 309 Times in 173 Posts	Re: Onan 4000 ky no start Hey Tonym: Remembered switching boards on mine and no difference. Just dug out copy of receipt for the repair and turns out I was mistaken. My fix was the voltage regulator, not the board. $149.00 in 2008. Sorry to aide in your confusion.

10-07-2017, 10:54 AM	#6
tonym Junior Member Join Date: Oct 2017 Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: Onan 4000 ky no start Thanks, Hacksaw Ill check it .