Carburetor Kit Comparisons

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Lurker Carl
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Carburetor Kit Comparisons

Postby Lurker Carl » Sun Apr 01, 2018 2:25 pm

Four carburetor kits, only one is not the same.
IH kit contains all 3 shaft seals with retainers, fuel drip seal and retainer, locking springs, idle needle, precision cut gaskets, OEM throttle shaft with 2 replacement screws, 2 replacement screws for choke butterfly, choke spring retainer, solid metal float needle with cage, and rebuilding instructions for Cub. Cost $45.00.

Valu-Bilt, Tisco, and TSC kits were identical, obviously all came from the same manufacturer. They featured poorly cut gaskets, a universal throttle shaft with 2 replacement screws, one shaft seal without retainer, Viton float needle with cage, and the wrong directions. Cost $22.00 - $30.00 each.

Valu-Bilt, Tisco and TSC kits for the Cub ALL have the wrong instruction sheet
I checked out these 3 brands of carburetor kits in 6 stores in 4 states – all had service info for the M instead of the Cub. Also, these kits are easily opened, half the kits I checked had pieces missing. No contents list is enclosed either, so buyer beware.

Still annoyed over these kits having the wrong instruction sheet, I remembered a little something I read recently on the message board. There was a comment about a carburetor gasket with the bore cut too small. Since I had problems with the bowl gasket, I measure the bore opening on the throttle body (0.94 inch) and the opening provided on the gasket (0.89 inch). The gasket reduces the opening by over 10%! All three of the off-the-shelf kits have the same problem.
In addition, those oblong holes let the gasket shift. So I trimmed the gasket’s bore even more. I’m not sure if it actually makes any difference, but I am sure you don’t need any extra interference when the bore is less than one inch to start. The gasket in the IH kit measured 0.955 inch and the stud holes are round.


The gasket below is way too big. Trim off the excess so it won’t interfere with the float or disintegrate into the fuel bowl and clog the main jet.

007.JPG (20.1 KiB) Viewed 1383 times

This cork gasket will have a lot of ‘squish’ when the castings are screwed together. In addition, cork gaskets tend to swell when wet. Make sure the idle air passage has plenty of clearance, it must be open for the idle circuit to work. Use a sharp razor for a clean cut. Little chunks of cork will clog the idle mixture valve and tiny idle holes located at the throttle butterfly.
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