governor/RPM questions on a JD A

[Clint Skarovsky]

Bear with me here guys, this might get long winded. I've had a '45 A with a PB for a couple of years and have been pulling it. Everything in the motor is unknown - it always pulls strong at 4600 and 5100, I've won something everytime out. It's very hard to find a happy throttle position between idle and running wide open. In fact it's never wanted to low idle well. A couple of months ago I bought a '51 A, the tractor is stock with the exception of a big nut carb. This tractor runs like it should, it will low idle all day, set the throttle and forget it, low RPM. So I swapped the big nut carb to the old tractor with a PB, at the same time I swapped to a dry air filter and G intake tube. It runs great, the problem is that any throttle movement and the engine just runs away. I definitely exacerbated the situation. I don't have a tach so I can't tell the RPM but it definitely feels like more than 1080.
As an aside, it doesn't necessarily like to rev under load, it's just a neutral/putting around thing.
Any thoughts? Thanks
 

[a1940jd]

if the length of the throttle linkage between the govenor arm and the carburator is not exactly correct the govener is rendered practically useless. It sounds as if you know for sure your govenor is working. If so its most likely only a linkage issue due to the pb and possible an aftermarket manifold changing the distance between the carburator and the govenor arm from its factory length. Check your IT manual for a clear explanation.
 

[Little Big B]

[Earl-IL]

Replies are good,but make sure the cotter key at the carb. isn't dragging.