RARE!! Thottle Body Part needed...

Wed Mar 10, 2004 1:21 pm

hey all,
I ordered a complete carb overhall kit from the good folks over at Carter and Gruenewald and it's on the way. In the meantime upon close inspection of my carb and a carb diagram on the cub server, it appears that my carb is missing some sort of plug that fits in the bore above the idle tube.. I broke the idle tube, and a new one is one the way, but there is definitly some kind of expansion plug missing on the top of the throttle body - I can look down through the hole and see where the idle tube will tread in. The guy at the dealer couldn't get that part. I couldn't find the part listed in the parts catalog on the cub server either. I guess I am just looking for a way to plug that hole, without interfering with the idle circuit. The local hardware sells little cork plugs that look like they would work... Will the gas rot out the cork? Anyone have an ideas?

You will see the little plug if you are looking at the carb from above (carb removed) it is between the throttle bore and one of the studs.

Peter Reynolds "the rookie" (1949 cub is finally back on all fours)

Thanks in Advance

Wed Mar 10, 2004 3:38 pm


Don't use cork! Keeping tiny particles out of the idle ports is very important. Most professional carburator rebuilders should have plugs in a variety of shapes and sizes, don't know if you could get the right one or not. If you do get one, you'll crack the casting if it's too big.

Try making a plug out of solder, it's soft and cheap. JB Weld may work as well, don't let it drip down into the idle passages - you'll have to work with the throttle body upside down and let it set up overnight before you turn it upright.

Be careful and good luck!

Lurker Carl

Wed Mar 10, 2004 4:31 pm

Peter, I'm guessing your talking about a welch plug. If so they should be easy to find. I think I've bought them in a variety pack, many sizes.

thanks guys

Wed Mar 10, 2004 9:30 pm

ah, a welch plug.. now I haven't heard of those.. i was looking for expansion plugs but no luck at lowes... where did you come across the variety pack? I figured a hardware would have them but lowes didn't.. i guess I'll keep looking around... thanks for the advice guys

Peter Reynolds

Thu Mar 11, 2004 12:04 am

I'll have to look into where I got them. Used to see them in small engine carb repair kits. You just set them in the hole and peen them with round flat punch to a tight fit. I'll look at my carb when I get home and see if we are on the same page.

Thu Mar 11, 2004 12:23 am

I would try NAPA auto parts or a carb rebuilding shop.