TO35 unsteady idle

[Justin-PA]

Hi all, I've got a nice 1955 TO35 that runs great for the most part. But it has always been a little rough at idle and seems to be getting worse. If I put the throttle lever the whole way to idle, the engine almost stalls, the governor kicks in and (usually) saves it, it revs up for a few seconds, then the engine slows down and it almost stalls again. This repeats until it actually stalls at some point. If I bump up the throttle to 900 - 1000 rpm it runs fine..nice and smooth.

Is this a givernor problem? I have not worked on the governor before...what do i need to do?

Thanks in advance for your help.
Justin

 

[Anonymous-0]

The idle mixture on the carburetor is way out of adjustment. If the throttle closes all the way it won't run on idle, but if the governor opens the throttle then it runs on the main. The governor confuses setting the idle mixture.

To start adjust, change the idle mix screw until its not hunting so much. Then hold the throttle closed overriding the governor and adjust the idle mix screw for fastest running. Or alternatively with the governor working, adjust the idle mix screw for the minimum throttle opening as the governor corrects for getting the mix better.

Its not sure that the idle mix screw is the only problem, it could be that the idle passage in the carburetor is plugged by varnish, or that the float needle and seat is worn and flooding it at idle.

Gerald J.

 

[Justin-PA]

Gerald,
You have me thinking. Another issue with this tractor is when it's shut down, I have to turn off the gas otherwise it starts to run out of the carb (albeit slowly). So I do have a float/needle/seat issue. I'll take a closer look at the carb and the idle screw.

Thanks!
Justin

 

[Jerry/MT]

Could be a dirty float valve or a worn one. Could also be a bad float adjustment. The Marvel-Schebler carbs are very touchy about float settings and most of us close the tank valve after shut down to preclude leakage as a precaution.

 

[Mark from the Fort]

I turn my gas off at the bulb while I'm still moving into the barn. Sometimes she dies, and I leave her set there 'till the next day. If it doesn't die, then I know that some or most of the gas is out of the carb before she sits for a day or two or three or four.
Always a good practice to shut off gas at gas tank.

 

[Justin-PA]

Thanks everyone. Tonight I adjusted the idle screw and the main jet screw and now it is running much better. Funny thing is I had done this before and wasn't able to get the idle problem resolved. I'll keep an eye on it and see if it continues to run better.

Justin