520h, Gov Ball Spacer Replaced, now rough running.

[Duramax7man7 506]

So I just finished up replacing the old plastic Gov ball spacer with a new metal one, cleaned everything up, made sure it was all put back together properly including the Stator, Spark ring and Module. I also replaced the timing cover oil seal and the rear oil seal while I had it drained of oil as it had a tiny seep from the rear bearing plate gasket. It was very brittle when removed.

 Anyway, I put it all back together and filled it up with oil and fired her up and she ran well for the few tests runs around the yard in all directions. I did notice hunting still after I stopped in front of the garage at a stand still. I pulled it front of the garage to put the 312-8s in first and parked this 520h, set the parking brake after dropping the throttle to idle... When I went to go back to pull the 520h in it had stopped while I was pulling in the other tractor.

 I went to start it up and a it puffed a little blue smoke from the exhaust trying to start it. Twice. I give it a little throttle and it turned over for about 5-6 second (Normally starts within 1 second) and it blew a little black smoke and started... It ran fine for a minute or so and then started sounding like it was missing and smells like it's running rich. I pulled the air cleaner and notice some fuel in the air box. And when I run the tractor with the air cleaner and box off, it seems to almost smoke from the carb?

 

 Any ideas? I checked out of the troubleshooting guide but didn't fully find a good candidate. Could this be something to do with the ignition module or valve seats?

Edited April 5, 2017 by Mastiffman

[Duramax7man7 506]

I guess I will check the carb for issues. I plugs and both are covered in black soot from fouling out. I dont know how the fuel pump works but could that be pumping to much fuel? 

 

 

[WVHillbilly520H 10,376]

The fuel pump is vacuum operated, never had one pump too much, they usually just give up, sounds like the needle stuck open,  sometimes you can get lucky and just pull the top off and clean it out, spray some good carb cleaner in all the passages you see, if there's black specs in there your fuel hoses have deteriorated from ethanol fuel and they'll need replacing as well as the filter, sorry I can't help with the governor issues never had mine apart yet, Jeff.

[cleat 7,260]

Not to sound like an idiot, but the choke is fully open ?

 

Just trying to think of what you could have bumped or moved doing the work you did assuming it ran properly before.

 

Make sure everything is plugged in properly and the condenser is hooked up.

 

Could the spark ring possibly have moved after it ran a while ? (check with timing light).

 

Any time I had a 520 do that it was the carb needing cleaning, just seems odd that your started after other work was done to it.

 

Cleat

[Duramax7man7 506]

Yep thats what it was. I pulled the carb (keeping the intake on! ) and pulled the entire thing apart. Blew everything out, used carb cleaner and blew it out again. Next time Ill be able to pull just the to off Im sure. Also pulled the plugs and cleaned them up with carb cleaner and air. Took a couple passes of finely folded 350 grit sand paper between the electrodes and cleaned it again. 

 

 

Shes good now. Fussy fussy these things are. Thanks for the replies fellas! 

[ericj 1,579]

the hunting and smoke , I would clean the carb and try it again

 

 

 

 

eric j

[Duramax7man7 506]

Yep its good now. Ran it for a few minutes and seems back to normal. Just weird how it ran fine when I got it back together and then it started hunting when I parked it and then when I let it Idle to move the other one it stalled out. Typical symptom of a dirty carb? 

 

Maybe I got some debris in the fuel line when replacing seals...? Shouldve been filtered out though. Maybe it got in the carb as I had the air box off. But I had the choke closed and it stuffed with paper towel and covered with plastic and zipped tied that.