IH 1600 grain truck

GeneMO · Oct 10, 2010

This is tractor related cause I had to use the tractor to tow the grain truck back home

)

My 1972 grain truck started running at full throttle. A neighbor told me about the governor butterfly, and to reach down through the carb, maybe it was stuck. Well I poked it with a long screwdiver, and it doesn"t appear to be stuck, but also appears to have spring tension on it.

Neighbors second thought was a broken governor spring, but again, it seems to have spring tension on it.

Wonder what"s up?

Thanks, Gene

Allan in NE · Oct 10, 2010

The carb throttle/governor assembly works exactly 'backwards' from the way you'd think.

The way that thing works is that spring pressure always tries to pull the throttle plate wide open.

Then, when cranking and/or running, engine vacuum (via carb internal passage) then forces 'er back towards the closed position and the idle stop by the use of the governor vacuum diaphram.

Has someone just worked on this carb or had the carb off?

Is the diaphram hooked up, is it leaking or is the linkage on correctly? How about the two carb throttle return springs (one inside the other)?

The little spring/linkage inside the "box" on the side of the carb okay and installed correctly? Has the diaphram arm to the throttle shaft on the shaft link come off?

Is that little "arm" on the end of the throttle shaft pointed in the right direction? If on backwards, the diaphram will assist the springs to "open" the throttle shaft.

I'm going by memory here, but hope I've kinda led you in the right direction.

Allan

Allan in NE · Oct 10, 2010

How about that big round "wound" spring on the shaft okay and in place?

Allan

Leroy · Oct 10, 2010

Did it all at once while running do it? Not familur with that truck except it is older and might have a mechanical link from peddle to carb like my Old Buick did (1948). Had it once while driving reve up to wide open and one of the ball assembly units had poped apart, just had to pop it back together.

GeneMO · Oct 10, 2010

Somebody mentioned vacuum. Wonder if a Line broke or came off. I'll go over and check. At least we got it towed to the farm shop yesterday.

The carb was gone over several years ago by the best IH mech in the area. I have ran it a good bit since the carb was gone through.

And yes, it happened all of the sudden while running. My son, just out of the Navy, probably had the thing to the floor coming out of the small town of Prarie Home, Mo.

What is inside the compartment on the right side of the carb? The one with anti-tamper wires running through the screws?

Thanks for everyones ideas.

Gene

Paul in MN · Oct 10, 2010

I do believe that is the governor.

Although most Loadstars were set up with a governor to limit the rpms, it is quite possible to run without one. But you must have a decent driver who is not trying to over rev the engine. The governor was put on to basically protect the engine from inexperienced and idiot drivers. The same engine was used in the PUs and Travelalls without any governor, and they had a long life. The 345 has good tolerance for higher RPMs, while the longer stroke 392 has less tolerance.

I just checked my 1963 IH service manual. The 345 is rated at max Hp at 4000 RPM, and max torque at 2300 RPM. It states the governor limits the speed to 3800 RPM. The governor on a truck has the function of limiting the RPMs, quite different from the function of a governor on a tractor which controls engine power to hopefully achieve a constant RPM.

If the governor fails on our Fleetstar 10 wheel grain truck, it will be gone. I can drive with the tach. Our '64 Loadstar (304 engine) lost its governor decades ago and the truck runs fine without it.

Paul in MN

IH 1600 grain truck

GeneMO

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Allan in NE

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Allan in NE

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Leroy

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GeneMO

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Paul in MN

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