I bought a reamer kit to install throttle shaft bushings in the throttle body. The throttle body is made of cast steel and eventually wears. This kit comes with the reamer and four 5/16" bushings. Here it is on ebay:
http://www.ebay.com/itm/Carburetor-5-16-Throttle-Shaft-Bushing-Repair-Kit-Made-in-USA-Bushings-Screws-/230761299891?pt=Motors_Automotive_Tools&hash=item35ba71ffb3&vxp=mtr
It is assumed that the reamer in the kit will be used with machinery to align the reamer properly. I don't have this equipment but because the reamer shaft is 5/16" in diameter it can be used as a pilot. The key is to grind cutting edges on the inside edges of the reamer:
Then, because the reamer is now being pulled not pushed there needs to be a place to grip the reamer with a tap holder:
Slide the reamer into the throttle body, attach the tap handle and start reaming:
I use a cutting fluid but oil came be used:
Apply to the cutting surfaces:
I reamed nearly all the way through then ream the other side using the nearly reamed hole on the other side as the pilot hole:
After reaming the second hole all the way I finish reaming the first hole. Then I clean the holes with denatured alcohol and start inserting the first bushing. After starting the first bushing I apply some permanent Loctite:
I press the bushing in until it bottoms out. Then I align another bushing and press that into the bore pushing the first bushing until it pokes out into the bore:
Then I cut off the excess bushing:
And file smooth:
I then trim the inside end of the bushing to be flush with the curvature of the carb bore. Then do the same on the other side...
