Grain Truck just idles

Marcel Gosselin · Jun 3, 2017

Co-worker just bought a late 70's ford grain truck.
Truck was parked for 8 years.
Runs, but just idles, had carb off and did not see anything.
they now believe it is something else other than carb.

strange thing 8 bought a mid 60 gmc grain truck last fall
filled up with gas onthe way home,
same thing after i started it. just idled
i took carb off and everything looked good with butterflys
put back on, but this time mine worked.

thoughts?
thanks?
Marcel

David G · Jun 3, 2017

Throttle cable or rod hooked up?

Bob Bancroft · Jun 3, 2017

I can't now remember just how it works, but I recall a carb. where the control does not open the plates, but allows them to open with spring or diaphragm pressure. Sometimes hooked to a governor through the distributor. So the only thing the control does for sure, is close the throttle plates.

Marcel Gosselin · Jun 3, 2017

in my yes for sure
and yes for sure with the ford

430WLPG · Jun 3, 2017

Would be helpful to know what engine and carb brand

Gene Davis (Ga.) · Jun 3, 2017

If this truck has a velocity governor it would pay to look at it. That thing has a butterfly that closes to slow
the engine down to keep it from over speeding.

RWT · Jun 3, 2017

Sounds like a governor carb.

The arm that the return spring hooks to has to be held down and if it isn't there is a spring to prevent a run away motor. The way the governor is set up
to work there is a spring under a cover that pulls the carb open. This allows the governor diaphragm to pull it closed when you nail the throttle. Most of
these governors don't work anymore but the carbs continue on.

You have to wind the piece with the return spring arm back against the heavy spring until you can hook it into a matching hook. That keeps that heavy
spring contained.

This is the best I can describe it at the moment. I could do if I was there and I am pretty sure this is your trouble.

RT (my 2?)

Fudd · Jun 3, 2017

Bob Bancroft has it. Sounds like the butterflys are sticking shut as they are opened with a spring. Spray them with carb cleaner
and work them with a screwdriver until they open on their own. When you open them with a screwdriver, you have to have the
throttle rod moved to the open position.

Owen Aaland · Jun 4, 2017

The governors pull the throttle plates closed with vacuum. I don't recall on the Fords but the GM ones would not allow the throttle plates to open if the little filter on the firewall became plugged.

Grain Truck just idles

Marcel Gosselin

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David G

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Bob Bancroft

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Marcel Gosselin

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430WLPG

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Gene Davis (Ga.)

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RWT

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Fudd

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Owen Aaland

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