Carburetor Rebuild Question

[lyle11]

I just rebuilt my IH carburetor using the complete Steiner kit. I replaced the throttle shaft. When you install the throttle plate on the shaft the Cub Service Manual says - Clinch over the exposed threads using special plier FES 36-4 to lock them in place. The Steiner instructions say to use a 1/4" rod pressed against the exposed screw ends and tap the head of the screw to slightly disfigure the screw and lock them in place. Be careful to not bend the shaft - my big concern, obviously. Are these screws prone to loosen? Could I use threadlocker even though it says for bolts 1/4" and up? What do you guys who rebuild IH carburetors do?

Thanks

[Bob McCarty]

I'm not aware of anyone clinching or using thread locker. I don't think I've even seen any of the 4-40 or 5-40 bolts that looked like they had been clinched down prior to removal.

Bob

[Gary Dotson]

Same here, Bob. A little thread locker couldn't hurt, I guess. I think loosening screws is more of a problem on engines that vibrate a lot, such as a lawn mower.

[Don McCombs]

I have seen some throttle and choke plate screws that seemed to be deformed on the ends, but not enough to completely prevent their removal. Hand tightening has always worked for me. If anything is needed at all, a little bit of Permatex green threadlocker would certainly do the job.

[lyle11]

Thanks. The screws I removed did not appear to be deformed. I was kind of surprised that the Steiner instructions suggested this thread deforming step instead of threadlocker as an alternative to the "special pliers" mentioned in the IH manual. From what I read, threadlocker type products have been around for over 50 years and would be less risky than the suggested procedure.

[twotone]

I've seen deformed screws on throttle plates. They unscrew hard, but come out ok if you're careful. I've never deformed them or used thread locker, and never had an issue.

[indy61]

I doubt it's an issue with the Cub's updraft carb but standard practice on aircraft or racing engines to stake throttle plate screws.

[Rick Spivey]

I believe staking these screws was a normal practice because, where will they end up if they do vibrate loose? You'll have more than a missing screw to repair....Maybe not as big a concern on updraft engines....