UB engine runaway

Still can't the MM UB to run right. The engine wants to run away from idle to WOT. Changed govenor 3 times, change linkage, changed carburator, rebuilt distributor. Checked for vacum leaks. From idle to WOT in about 30/45 seconds. What am I missing? Thanks
 

This problem comes up on this board about once every year or two. Have you checked the archives?

As long as no other problems like outside air getting past the carb. throttle shaft (Worn?) or in the manifold somehow,(Crack or gasket leak?) And if you have a good working governor assembly, your problem probably is the link between the governor and the carb.

I don't know how to set it up so it idles and is also very responsive, but there may be instructions in the archives.
 
Does your U B have a replacement manifold with a slightly longer "throat" to carb. I had that experence and had to shorten throat to get linkage to work freely.
 
my brother made a new rod from the governor to the carb on his U. i dont know what yours looks like but it has to have a V bent in the rod. he did that with his and i think it has a little play in it also so the governor will work right.
 
Thanks for all the advice. I have all the linkage disconnected. Carb throttle shaft has over 2 pounds of weights on it. Governor locked at idle. tractor will still continue to gain RPM"s until WOT
 
Is the governor moving the linkage with the weight on it? Or is it running faster with the throttle blade closed?
 
first off if the governor is working CORRECTLY you could sneeze on em and change the engine speed thats how tempermentle they are unhook the rod from carb to governor and start the tractor up run the throttle shaft by hand on carb wide open and hold the governor rod in other hand at high rpm it should pull your hand down i have had my share of problems with these also and if it pulls hard against your hand its simply linkage it doesn't take much on them and they won't run i had a ub that did the same thing it would go from an idle to wide open i bought it that way guy had a drawpin hanging to keep it idled down it was simply outta adjustment hope this helps you
 

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