How much play is too much
Thread Starter
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
How much play is too much
in the throttle shafts? I'm sure I have too much. 
Have an original # rebuilt Q-jet on my 454. Have the mixture screws 5 turn out & it's still lean. Took it off yesterday to double check everything and there is at least .040 play in the primary throttle shafts 
I would assume this is way to much as I can get a sizable RPM increase with propane at the shaft ends
Jim
Have an original # rebuilt Q-jet on my 454. Have the mixture screws 5 turn out & it's still lean. Took it off yesterday to double check everything and there is at least .040 play in the primary throttle shafts I would assume this is way to much as I can get a sizable RPM increase with propane at the shaft ends
Jim
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
There aren't any bushings on a stock Q-Jet throttle shaft.
Lars
V8FastCars@msn.com
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If your carb could stand a rebuild and fine tuning, you would do best to send it to Lars and have him do the throttle shaft bushings and the other work. He is very reasonable on his prices, does great work, and usually has fast turn-around. If your distributor has not been serviced in many years, just send him your dizzy, too. You will be amazed at the difference in your engine's performance, if he does that work.
Thread Starter
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
That sounds a little excessive. The Q-Jets had pretty sloppy shafts even when brand new: You can take a new Q-Jet and wigggle the shafts quite a bit, but not .040". Normally, the play is excessive when the carb won't return to a consistent idle due to the throttle plates "cocking" slightly in the throttle bores. If you need help with it, I can install bushings for you - the carb will usually only require a bushing on the primary driver's side since this is the only location that has any load on the shaft. You can e-mail me for info.
There aren't any bushings on a stock Q-Jet throttle shaft.
Lars
V8FastCars@msn.com
There aren't any bushings on a stock Q-Jet throttle shaft.
Lars
V8FastCars@msn.com
The distributor has been refurbished already with new bushings, gears etc.
Thanks
Jim
Race Director
Joined: Sep 1999
Posts: 11,361
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From: Plano TX
Thread Starter
Melting Slicks
Joined: Jul 2001
Posts: 2,609
Likes: 12
From: Massapequa Park NY
No evidence of an bushings that I can see
