: "exhaust cough" at idle. Does not occur under load.I've replaced plugs, carb clean & kit, new wires, compression 150 -155 across all cylinders. Runs great & clean under load like bushog or plow. Any suggestions?? Please help.
Have you checked your distributor advance? Could be staying advanced in timing at idle. The two small springs could be disconnected from the weights, or excess wear. Check the timing with a timing light if available.
Older tractors often loose the benefit of the automatic timing advance for faster engine speed, and an engine will run good on one end of the scale but not the other.
Send me a direct email if you might want a few of my ideas on how to get the timing set easily.