identify my CAT

The throttle control rod doesn't directly link to the throttle.

Instead, it can only pull the throttle closed or block it opening, opposing the action of the governor spring. When you push it in, it allows the governor to open the throttle (spring pulls it open) until the rpm exceeds the setpoint and the governor weights push on the throttle arm and force it closed a bit.

Sometimes you see the little block on the wrong side of the throttle to governor linkage pin and then you have no way to slow the engine to low idle at all.

Stepehn and ccjersey,

Thanks.
I think you hit mine on the head that is the stop/block (if you will) is not in the correct position therefore it is not allowing me to reduce the idle once it gets going.
I guess I will have to play with it a little more to see how that block can be turned 90 degrees or more to contact the govenor.

Thanks for the input. I saw nothing on a diagram of the linkage in any manual I looked through other than a picture of the carb.

Tom

So in reading other posts on the D2 serial number there is almost nothing outwardly to differentiate a "SP" at the end of the number from any other cat. It seems like a mostly internal difference?

That would seem to follow on mine as the only thing out of norm is the PTO.

Any idea on year of this bugger 5J4857SP?

Thanks,

Tom

So in reading other posts on the D2 serial number there is almost nothing outwardly to differentiate a "SP" at the end of the number from any other cat. It seems like a mostly internal difference?

That would seem to follow on mine as the only thing out of norm is the PTO.

Any idea on year of this bugger 5J4857SP?

Thanks,

Tom

Your D2 is a 1941, the production numbers for that year started at 5J3551 and ended at 5J5147. The "SP" could include special gearing inside the transmission, larger front idlers, basically things that would have required special attention to be paid on the assembly line.