Worn Throttle Shaft - carb balance problem

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undysworld
Norway
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Joined: Fri Apr 16, 2004 8:08 am
Location: Blue Mounds, WI

Re: Worn Throttle Shaft - carb balance problem

Post by undysworld »

Hi Miles,

I'll definitely put the question to him. But I don't know if he's any better with a computer than I am (which is lousy).

From what I understood from our conversation, he didn't think that sort of plan would work in my case. The concern is that: because the holes are no longer exactly centered, if he follows the existing course the shaft will not be centered in the carb bores. Then the throttle plates will not close precisely, etc.

Also, he planned to install the brass sleeves, and then drill out the sleeve's center to the exact bore he needs. So unless you had sleeves with the exact i.d. you needed, it's still more than a one-step process. :(

I had some shade-tree ideas on how to do it, if I was going to attempt it myself. But the more I look into the work, the more it seems like a guy with the right knowledge and machines would have a lot better chance of actually getting it done right. And I don't want to think about getting it wrong. :roll:

Stay tuned...

Paul
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Jimm391730
United States of America
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Re: Worn Throttle Shaft - carb balance problem

Post by Jimm391730 »

Obviously it is best to have it done "right", but there are shadetree mechanic methods of doing it. McMaster Carr has a 12" long drill bit that is 8.333mm in diameter (2955A21, $36) and you could grind it just slightly narrower for half its length to act as a pilot. Even if the shaft ended up a smidge off of original center, the butterflies can "float" a bit on their screws to properly center in the bores, THEN tighten their screws. It just depends on what resources you have available -- professional machining, or a "gotta get it done myself" attitude.
Jim M.
712W and 710M
undysworld
Norway
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Location: Blue Mounds, WI

Re: Worn Throttle Shaft - carb balance problem

Post by undysworld »

Jim,

Oh :!: I didn't realize there was wiggle room with the throttle discs.

But I guess that really makes sense, given the sort of "fix it in the field" attitude that seems to be part of the Pinz's design. :idea:

So it's perhaps a much less precise situation than we're making it out to be. Maybe we're over-thinking the wheel.

It'd be interesting to take two carbs, fix one the "right" way, and fix the other one the shadetree way, and see what the differences might be.
Erik712m
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Location: Wichita, Kansas

Re: Worn Throttle Shaft - carb balance problem

Post by Erik712m »

Paul, Could be wrong but I beleive T-lo doe's the same thing you're having done. i believe it's mentioned in the locked tech section.
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