The Stovebolt Site Forums The Shop Area Engine Shop Who can install throttle bushings in a Rochester ?

I recently replaced the Rochester B carb on my 235 Powerglide engine with a Carter YF 2100S. I am very happy with the Carter.

The Rochester has been with me a long time however, bought as a remanufactured carb about 25 years ago. Can't bear to throw it in the junk pile, so I decided to clean it up and give it a rebuild and set it on the shelf. It actually is in very good shape. It has been in continuous use these last 25 years and is very clean inside. The castings seem very straight and not warped.Everything came apart very easily. In fact the screws holding the body together were just a little more than finger tight and looked like new.

I think the major problem with this carb is that the throttle body is wallowed out at the throttle shaft bearings. It always leaked gas here, and I am sure I have a vacuum leak at this point. Obviously this was not addressed by the rebuilder 25 years ago.

Do any of you good folks know of a shop where I could send the throttle body to have bushings put in?

Thanks,

Kurt

What is the condition of the shaft? If it's worn, you'll need to find a new shaft to go with the bushings. The throttle body will need to be reamed oversize, then bushings will need to be pressed in, and line-reamed to fit the shaft. If the shaft is worn, the fit won't be much better.
Jerry

Jerry,

Thanks. Do you know of a shop that can install the bushings? I might be able to chuck up the body in my (new to me) lathe and drill out for the bushings, but if I can find a shop that will do it for a reasonable price, I'll go that way.

Kurt

Kurt, I have the reamer and some bushing I could loan you if you want to do the job yourself. Send me a note with address if you want. It's a pretty easy job, hardest part is getting the throttle plate out. I use a standard bench top drill press to do the reaming. Even a worn shaft will tighten up to a point with new bushings.

joe

Joe,

PM sent.

Kurt

Kurt, here's a sneaky trick that might not be obvious to a new machinist. Chuck a drill bit that's about the size of the shaft into a 3-jaw chuck, and clamp and shim the throttle body onto the lathe carriage so it's a slip fit over the drill bit as you move the carriage back and forth. Then substitute the reamer for the drill bit, turn the lathe on, and use the carriage feed to advance the throttle body over the reamer. You'll get line-bored holes that way that are in perfect alignment. Once the bushings are pressed in, use the same setup procedure to ream them to fit the throttle shaft.
Jerry

Jerry,

Thanks for the tip. That's close to what I was thinking. I have used basically the same trick when aligning a broken stem for brazing on the DLTX-10 carb for my '37 John Deere tractor.

I do have a four jaw chuck for my lathe, so it shouldn't be too tough.

Kurt

When I get stumped I talk to a shop in Auburn. WA. and tell them what I have. They have always had me send it to them and it is always returned shipping paid back to me by them. www.carburetion.com

Normbc9

This isn’t that hard for a do it yourselfer but I’ll guess ten times as many people have access to a drill press over a lathe. To square the throttle body to the spindle mount the throttle shaft in the drill chuck, slide the throttle body over it, and mount it to a block of wood. The general rule for reaming is half the speed and twice the feed of what is used for drilling which also applies when enlarging a hole with another drill. Since the throttle body is made of cast iron and the shaft of steel the wear will be biased to the iron allowing re use of the shaft at least some of the time.