Throttle shaft play...how much is too much?

Rob1

Member
Hi,
As the title suggests. Butterfly shaft side to side movement is about half a millimetre, but the shaft can also move around in its housing by half to a third of a millimetre as well. I'm guessing this enough to cause a vacuum leak....?
Cheers,
Rob.
 
Is this on an SU carb? If so that’s pretty bad. I’ve seen wear as little as 0.005” (0.125mm) cause problems with SU carbs. Difficulty in holding tune, rich idle and under par performance.
 
Certainly sounds badly worn. The side to side is the more alarming, if the butterfly is firmly attached to the shaft there should be barely be any side shake.

Yours
Vern
 
Radial float on the shaft should be virtually nil, axial could be a small amount on full throttle, very little throttle closed
 
Well, dang. Sounds like I've found a problem (yes, sorry on the SU carbs). Car has 35 000mi on the clock - I wonder if this is premature wear or if it's been 'round once already....
 
Back
Top