Lost Power after Carburetor Shaft Broke

Phil - MO · Oct 13, 2019

JD 430 2 cyl. gas tractor.
While brush hogging in very rough ground and thick stuff the throttle shaft to the carb broke and tractor ran at very high rpm until I could shut everything off. Didn't know a 2 cyl. could turn over that fast.
Carburetor is now back together with carb parts and tractor starts and runs good but does not have much torque under load.

Wonder what could have caused this and what should I check out.

Phil

old · Oct 13, 2019

Did you get eh butterfly back on the shaft correctly?? One can install the butterfly in such a way that it does not open up and that will in turn cause it to only idle which means very little power

r.w.b. · Oct 14, 2019

Throttle shaft arm might be mounted at wrong angle,thus lazy governor.unhook throttle rod,pull hand throttle wide open,the connector should be set just short nuff it wont go in hole in arm. Start there,if its jumpy surge when under load lenghten it a small bit,if doggy low power shorten it a small tad

Phil - MO · Oct 14, 2019

Thanks for the info.
Butterfly is free. I think the throttle shaft is different because I had to pull the governor shaft quite a ways to insert into arm of the throttle shaft. (Hard to work on in the brush) but I idled home and will work on it some more.
Good to know the proper arm adjustment.

old · Oct 14, 2019

If you think the shaft is not correct try this. Close the throttle down to an idle position. Then as you open it up watch and see if the shaft opens up as it should as you open the throttle to the high RPM position. It should open up the throttle on the carb to wide open when you do that. If it doesn't then an adjustment needs to be done or the shaft is not the correct one

Phil - MO · Oct 15, 2019

Pulled carb. and checked everything out. Throttle shaft was installed right.
Found if I open high speed carb adjustment up an extra turn (richer) runs much better.

Hate to adjust the governor but I think you guys are right that the arm is at a little different angle on the new throttle shaft.

How do I extend the arm from the governor to the carb? The air cleaner hides the governor right now and may be easy to do. Working in the rain right now and will adjust later.

Phil - MO · Oct 15, 2019

Found governor adjustment on JD 420 on web. Should be same parts as 430.
Will use that. Thanks for all the help.
Phil

Lost Power after Carburetor Shaft Broke

Phil - MO

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old

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r.w.b.

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Phil - MO

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old

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Phil - MO

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Phil - MO

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