48 Farmall C Idle

Tim Workman · Jul 30, 2015

Hey Guys,

I'm hoping y'all can help me out. My 48 C seems to be running high at idle. It starts out a little lower but once it warms up, I would guess anywhere between 200-300 rpms higher than what it should be. I've got the linkage on the carb back against the stop so I can't go any farther that way. I've added a couple washers on the mag side to tighten up that linkage. I'm pretty baffled at this one.

Any ideas out there?

Bob · Jul 30, 2015

Are you saying you have the idle speed adjusting screw on the carb's throttle lever backed all the way out and it still idles too fast?

If so, butterfly screws into throttle shaft may need to be loosened a bit and the throttle plate tweaked into position so it's centered in the bore, or, for that matter, the screws may have come loose or one may even be missing.

If that is not the case, the LENGTH of the throttle rod from the governor lever to the throttle lever on the carb needs to be adjusted in length.

Dave from Texas · Jul 30, 2015

Have you check the disc in the Carb to make sure it closes tightly? On one I had to cut additional threads on the governor rod to slow it down. I think sometimes all the connections in the governor wears and are no longer tight.

rustyfarmall · Jul 30, 2015

Possibly need to replace the manifold gasket, and also the carb to manifold gasket.

Tim Workman · Aug 4, 2015

Thanks for your help everyone! I have a feeling it's in the governor as that is the only place I haven't inspected or tore into yet.

Again, appreciate the help!

Ozlander · Aug 4, 2015

Grab the rod that goes to the carb and pull it all the way to idle. If you have the idle screw all the way in, you should kill the engine when you do that.
If not, the problem is air leak in the carb to intake or intake to engine. Could be the throttle shaft leaking air.

NoNewParts · Aug 5, 2015

easy first
carb, like said holding the rod so the idle is at the stop,
screw backed out all the way it should stall, if the screw is adjusted properly for the low rpm idle, holding the rod, it should chug along happily at low idle...forever.
If it won't even after adjustment, check for air leaks (throttle shaft usually) or the butterfly messed up.
Once that is right, governor to carb rod adjusted by the book.
Then, lastly, move on to the governor...sloppy stuff, arms, bearings, springs, etc

ps remember..nothing is allowed to touch that governor to carb rod, clean, free, no effort, junctions and no contact with nothing

J.Wondergem · Aug 5, 2015

If this started doing this, and didn't do it before, I agree with rustyfarmall. Might have a air leak.

48 Farmall C Idle

Tim Workman

New User

Bob

Well-known Member

Dave from Texas

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rustyfarmall

Well-known Member

Tim Workman

New User

Ozlander

Well-known Member

NoNewParts

Member

J.Wondergem

Well-known Member

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