Throttle shaft much is too much?

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....?


Well-Known Member
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.

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....