Should know

[Dusty B]

Something I should know but don't and its networking! Are the threads in the IH carb non-standard? I've had some that were stripped out/bored out and replaced w/bolt and tap but have 2 different ones that appear to have good threads but standard bolts do not work!?? Is the best/easiest solution tap them to standard thread or get the correct bolts?

[Clemsonfor]

There going to be standard!

[Bob McCarty]

Dusty, are you talking about the studs that hold the carb to the manifold? If so, the carb end is 1/4-20 and the manifold side is 1/4-28. The carb end often gets stripped out and the stud is replaced with a bolt and nut. All of the carb threads are standard as Clemsonfor said.

[Clemsonfor]

Often times when a standard hole strips out folks will go to the next larger metric cause you can often run the tap up in there and not drill it out. Not really the correct way to do things but it often will work.

[staninlowerAL]

Carb OEM Fuel inlet is 1/2 x 20 bolt thread NOT pipe or tubing. Accepts a 5/16 male tubing thread nut. Some people try to use pipe fittings and destroy the threads in the soft metal. Same situation on the OEM fuel sediment bowl/fuel cutoff valve. There are ways to correct the problem: helicoil, special custom adapters, etc. Check the HOW TO subforum FUEL topic for some ideas. Send me a PM if you want more info. STAN

[Glen]

Hi,
I guess you meant the threads holding the carburetor onto the manifold.

The IH carb originally has studs that hold it onto the manifold.
The threads in the carb are coarse threads, and the threads for the nuts are fine threads.

Below is a listing at TM Tractor showing the original type of studs, the sizes are in the listing.

http://www.tmtractor.com/new/fl/405fp.htm