300 idle metering jet

Dave S. · May 26, 2015

Have a 300 carburetor with the idle metering broken off below the surface of the carb. Does anyone know the size and number of threads per inch? Want to find a tap to clean up the threads after it is drilled out.

Bob in wc Ia. · May 27, 2015

Dave S.

The thread size is 5-40. Use a #38 tap drill. Good luck with your project.

Bob

rustyfarmall · May 27, 2015

(quoted from post at 05:01:48 05/27/15) Dave S.

The thread size is 5-40. Use a #38 tap drill. Good luck with your project.

Bob

I am thinking it is 4-40?

Bob in wc Ia. · May 27, 2015

rusty,

I just measured one I had laying on the bench. Measures .125 on outside diameter of the threads, 4-40 would be .112 .
I'm pretty sure 5-40 is right, but I've been wrong before .

bassmasta76 · May 27, 2015

Ouch, I feel your pain. I had that happen on my H. I finally got the remains of the old jet out and thought it was clean.. started screwing in the new one and it snapped off. Had to do it all over again. At least the new jet snapped off with enough threads to still be usable. what a pain in the rear.

best of luck to you!

--b

D Slater · May 27, 2015

Bob if my memory isn't failing me you are correct.

Dave S. · May 27, 2015

Thanks for the replies, I appreciate it,

Dave S. · May 29, 2015

Got the jet drilled out, chased threads, put new jet in and carb is back together. 5 X 40 was the right thread size. Thanks

300 idle metering jet

Dave S.

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Bob in wc Ia.

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rustyfarmall

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Bob in wc Ia.

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bassmasta76

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D Slater

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Dave S.

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Dave S.

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