MF 175

kdf101 · May 31, 2020

I have a 1973 MF 175 with a gas Perkins engine. It has a new carb on it, but still runs rough, which I assume may be points and timing, it also has new plugs. The main issue is when I start it, the rpm痴 go up and down at random, and the engine will just rev all the way up to almost max without the throttle lever being touched.

kdf101 · Jun 4, 2020

New ignition parts, I replaced all of them from points to coil, seemed to have fixed the miss. The tractor still surges to full throttle though, without any input from me. The throttle lever can be moved about 1'8 inch and the tractor goes to full throttle. If i don't touch the throttle, the engine will slowly pick up speed until it is going full throttle.

Roadworthy · Jun 4, 2020

You say you got a new carburetor. Is it new or just new to you. Rebuilt? It sounds like a carburetor issue. If the engine speeds up like that it's getting fuel from somewhere.

kdf101 · Jun 12, 2020

It is a new one. I got the missing figured out, Replaced points, condenser, cap, rotor, coil. One of those did it. Timing has been done by ear but not quite right. Where is the pointer that you reference when you use a timing light? I have only timed cars before and there is usually a tab of some sort so you can time it.

One other problem is that I assume the governor rod/throttle linkage needs adjusted. If I move the throttle lever at all, the tractor motor gradually speeds up on its own until it is wide open. Pushing up on the throttle lever brings it back to idle, but there is only about 1/8 inch of movement between idle and wide open.