M5 with same issues

[Steve Fawks]

Cleaned the fuel tank, new sediment bulb assembly, new fuel line and after one lap around the shed at good speed, it sputters and I have to put in the clutch and let off the throttle. Carb was kitted, but not by me.

The intake above the carb is frosting up in 50 degree weather.

Any ideas?

BTW, what is that contraption beneath the carb that the linkage connects to?
 

[Alan K]

Have you checked the spark plug wires? From what Ive been told the silicone ones dont work well under load. I had that problem on my M670 being the wires that the previous owner had on and, along with a bad coil. The governor is what is under the carburetor. Mine ran decent at idle but then started to miss at about 1200 RPM.
 

[r aiken]

As for your carb frosting, that is normal when the temp. and humity is rite. When a liquid (gas) is vaperized it gets colder.
The contraption is the govener. It mantains the proper engine speed.
 

[r aiken]

Most older tractors, you have to run with the choke pulled out a little untill warmed up.
 

[Steve Fawks]

Thanks for all the advice, but I think my son-in-law clued me onto the solution. He said that he had an 8N acting like that a few years ago and it turned out to be an issue with the air intake/cleaner.

I figured that would be easy to test by disconnecting the intake hose from the carb, clamping some fabric over the carb, and seeing how it ran. It ran circles around the barn until I was tired of running circles around the barn!

OK, fuel, fire, and AIR! Last thing that I expected to look for, but that did it.

Ready to tear up the farm when I get it all cleaned up.