you might need to clean it to get it running. sounds like its starving for fuel at high rpms.

 

I would check/replace fuel filter, check fuel tank for debris, fuel line, run some Sea-foam in system, check that engine covers are free of debris, and this is assuming new plugs with the new coil and wiring was inspected including key switch, etc.

 

SOunds like fuel pump,and the motor is sucking the float bowl dry.

 

Try a little seafoam directly in the carb.....it will smoke alot...but cleans as good as can be done without disassembling it.

 

All good suggestions. Thanks for the replies, guys.

I'll try seafoam in the carb and see it that helps.

 

My 2 year intermittent electrical onan nightmare - confirmed with no spark when 'dead', and would restart when cool only to die at an unnamed time later- turned out to be some kind of electronic ignition module. My friend and mechanic had gone to Onan school year ago and called up to them and they stated this not uncommon failure. Well now it runs like new, at least I think so. I never had it new, but it could not run better.

I hope the carb clean works, much cheaper.
My two cents.

Yamadoo

 

I was able to start it and slowly pour some seafoam through the carb. After a few ounces I dumped some in quickly and shut it down. I waited 10 minutes and I couldn't get it started immediately. I thought "if it's starved for fuel, I'll spray carb cleaner in it." I tried that and it still wouldn't start. I did finally get it started and put it away.

Now I need to think about this ... fuel problem or electrical problem?

Any thoughts on what tests to do to see if it might be the TDM? (or other electrical component)

 

check your float level.. it might not be letting enough gas in

 

If it were me,the next time it stops,I would remove the top of the carb and see if there is any fuel in the carb.If is empty,start with new fuel lines,fuel filter,and then go to fuel pump.When it dies have you checked for fire at the plugs?

 

If it dies every time you start it or you can go to WOT to make it die, than you can check to see if it is loosing spark fairly easy. All you need to do is put an induction timing light on one cylinder. If it cuts out and the motor stops it is ignition (electrical) if it starts to die out and the timing light is still flashing than it is gas.
Carb spray as in carb cleaner is not flammable enough to run a motor. If you spray either in it that would start it if it is staving out. Carb cleaner would only flood it out with non combustibles.
Just some of my thoughts

 

MY DEERE you are right on the spray,what makes them combustable is the propellent,these motors are so simple,you got have fire,gas and air,if you don't have one then you have found the problem.

 

All great suggestions but it seems your still trying to isolate between fuel or electrical problem.
If you don't already have one, go purchase a spark plug tester. Perhaps even 2. I picked one up from the spare parts bin at a NAPA for around $2.
Just as soon as it dies, clip on the spark tester and try to start it. If you have good spark on both plugs it's a fuel issue. If no spark - you've atleast narrowed it down to the ignition subsystem.
Good luck
Dave.

P.S., I'd recommend to stay away from carb cleaner, ether or any other quick starting chemical as they all can do damage to your engines internals. If you suspect a fuel related issue, purchase one of those cheap turkey injectors for a couple bucks, draw some gas up into it, doesn't take much, then inject this gas directly into the carb. Since the engine is designed to start and run off of gasoline, why not direct inject it to aid in troubleshooting starting problems?

 

:thanku: for all of these suggestions. I do need to narrow down between fuel and spark. Picking up two inline plug testers is a good idea, and so is using a turkey baster with gas. Once I have the plug testers and I’ll run it again.

 

** update **

It ran well for 45 minutes today! Will it continue to do so? raying:

I had ordered spark plug wires from onanparts.com, which arrived today. I checked the resistance on the old wires and they seemed OK, but I wanted to replace them anyway. I had to go to three parts stores before I found an inline spark plug checker. By the time I was ready to test it out, it had cooled down some outside, but I think running for 45 minutes should have caused it to cut out if it were heat related.

What had been done: replace coil, condensor, plugs, wire and "cleaned" carb with seafoam. Was it the new wires or "cleaning" the carb, or a combination? I'll run it tomorrow for a hour and see what happens.

Thanks for the suggestions.

 

To eliminate the fuel line issues try this, get a gas can and get it elevated higher than the engine. Get a length of fuel hose from the can that can be put right on the carb, then siphon the fuel to the end of the hose and get it put on the carb (do not let the fuel come out of the line while doing this, I find a small C clamp or something to squeeze the hose while connecting is a good idea) then start the engine and run it at idle then at full throttle and see if it runs good. If so then you may need to replace all the lines from the in-tank pick-ups to the reserve valve and then to the fuel pump and from the fuel pump to the carb. Don't forget to replace the crankcase pulse line that goes into the back of the fuel pump.

 

I just carried a plug with me and had the side panel off and checked for spark when she would die
Yamadoo

 

** update 2 **

I took it out today - 90* with dew point of 70, so it was hot enough

In the first 5 minutes, it hesistated and almost died, but I turned off the PTO, throttled down and it was fine. Back to WOT with PTO on and I was cutting for 55 minutes without a problem. It died after 55 minutes, but I was able to restart it and finish up the last 5 minutes without another issue.

So, I'm fairly happy. Maybe a real carb cleaning and rebuild will make it run well. Hopefully it isn't still an electrical issue that is creeping up.

Thanks for the help and suggestions.