how common are busted rings due to hitting the wear ridge?

[MCompact]

Originally Posted by caprice_2nv

I've been driving mainly just cars with qjets for the past 16 years. I've had some problems with them (choke pulloffs, needle and seat plugged up, jets plugged up) but none of them ever wore out the throttle shafts. I've heard it can happen but I definitely wouldn't say "most". They've been pretty reliable for me, but I would occasionally have problems. But these cars also sometimes would sit 6 months of the year while I was driving the other one (summer/winter car - I only insured one at a time up until a few years ago). They would usually start right up and run fine after sitting that long too.


I learned the ins and outs of Q-jets during my misspent street racing youth; I still get called on to rebuild one from time to time. Once you understand how they work you'll find that you can dial in almost perfect part-throtte and full-throttle calibrations- assuming you have access to a wide selection of primary jets/metering rods, power piston springs, and secondary metering rods and hangers.

 

[Silverado12]

Originally Posted by MCompact
Originally Posted by caprice_2nv

I've been driving mainly just cars with qjets for the past 16 years. I've had some problems with them (choke pulloffs, needle and seat plugged up, jets plugged up) but none of them ever wore out the throttle shafts. I've heard it can happen but I definitely wouldn't say "most". They've been pretty reliable for me, but I would occasionally have problems. But these cars also sometimes would sit 6 months of the year while I was driving the other one (summer/winter car - I only insured one at a time up until a few years ago). They would usually start right up and run fine after sitting that long too.


I learned the ins and outs of Q-jets during my misspent street racing youth; I still get called on to rebuild one from time to time. Once you understand how they work you'll find that you can dial in almost perfect part-throtte and full-throttle calibrations- assuming you have access to a wide selection of primary jets/metering rods, power piston springs, and secondary metering rods and hangers.

I was always a fan of the Q-Jet too, but I never really had to work on one; that's what I liked about them.

 

[Trav]

Originally Posted by caprice_2nv
Originally Posted by Trav
Yes carbs get a lot of blame and deservedly so. Back when carbs were the norm more of them were out of whack then those properly tuned for various reasons.
The old Q jets were a balancing act, most had air leaks at the throttle shafts causing it to run lean and leaking bowls on top of that causing it run rich, they needed a bushing kit and better float bowl seal along with some jet tuning to get them anywhere near right.

They all had some real winners too, yes they could all (except the ford VV) be made to run fairly well but the vast majority of them fell into disrepair and stayed that way.


I've been driving mainly just cars with qjets for the past 16 years. I've had some problems with them (choke pulloffs, needle and seat plugged up, jets plugged up) but none of them ever wore out the throttle shafts. I've heard it can happen but I definitely wouldn't say "most". They've been pretty reliable for me, but I would occasionally have problems. But these cars also sometimes would sit 6 months of the year while I was driving the other one (summer/winter car - I only insured one at a time up until a few years ago). They would usually start right up and run fine after sitting that long too.


Google Q Jet throttle shaft wear. By the time these things need service most need the kit, not just a few but most and I have been rebuilding them over 40 years.
You have either been really lucky or not noticed it because they are under tension.

https://quadrajetparts.com/quadrajet-carburetor-primary-throttle-shaft-bushings-p-287.html

https://quadrajetparts.com/quadrajet-throttle-shaft-bushing-c-128_34.html