How much play should there be in the secondary throttle shaft? I was tracking down a vacuum leak and discovered that when carb cleaner was sprayed on the secondary shafts the idle sped up. There is a few thousands of horizontal movement on the shaft. I realize that there is no way to totally seal the shaft but this seems excessive to me. I'm not sure if it's always been this way or not. The original leak was a warped carb spacer. Any thoughts?

Durham Missouri

Most secondaries don't get used enough to wear the shafts excessively I would think. The spray of carb cleaner could be getting sucked in a different area, possibly below. If you had a warped spacer at one time and tightened the carb against it, it may have warped the carb base?

I replaced the spacer and the gaskets. The carb base is fine I checked that before I reassembled it. It's definitely the shaft. I sprayed the carb cleaner with the straw to better isolate it. The only time it changed was when directly sprayed on the shaft. The base and spacer were fine with no change in idle. The carb has less than 1500 miles on it. I was thinking maybe a production error.

Durham Missouri

It could be a  production error.  Contact Summit about it.  They should know their carbs.


Lawrenceville, GA

One would think so Charlie. I plan on calling them but if you ever talked to their tech support you would be disappointed. The 2 or 3 times I called about something related to their carbs it was a waste of time. Basically salesmen with different titles.

Durham Missouri