Help needed with 100 carb rebuild

drhntrrmw · #1 12-14-2010, 07:35 AM

Hello all,

I am rebuilding the Carter carburator off my 100. In the process of tearing it down the small brass screws that hold the "butterfly" onto the throttle rod broke off.

I probably didn't explain this technically correct so if you need clarification or pictures let me know.

Thanks for all the help,
Rob

ljones · #2 12-14-2010, 08:03 AM

drhntrrmw,
if they broke with threads still on the back then you need to file the remaining threads off so you can get the shaft out, then you need to drill them out and retap them if you want to reuse your old throtel shaft (they are size 3-48). You can also remove the old shaft and get a new throttel shaft kit but they are $35-$40.

Matt G. · #3 12-14-2010, 08:37 AM

That is why you should carefully grind/file off the exposed threads on the screws before removing them. They are peened over at the factory so they don't vibrate loose. Never re-use them, either. They seem to yield when they are tightened properly. I don't think I've had more than one or two of them that didn't twist off when I tried to re-use them.

drhntrrmw · #4 12-14-2010, 11:59 AM

Thanks for the help.

When putting it back together with new screws should lock-tite be use to keep them from coming loose?

I have the carb on my 122 that needs to be rebuild as well. Is it even necessary to take the throttle shaft out for a rebuild?

Matt G. · #5 12-14-2010, 12:18 PM

I use new screws with lockwashers and put a drop of blue loc-tite on the threads before installation. If the throttle shaft is loose in the carb, it must be removed to install the throttle shaft bushing.

drhntrrmw · #6 12-15-2010, 07:42 AM

Is it necessary to screw out the brass seat that is up inside the stem that drops down into the bowl?

Thanks again for all the guidance, I'm there will be plenty more questions to come!

B-Brush · #7 12-15-2010, 07:51 AM

Just my 2 cents but if you try to unscrew that fuel nozzle your askin for trouble it is very easily stripped and hard to find a new one best bet is to soak it in one of those cans of carb cleaner you can get it at your local auto parts for around 20 bucks

JaysNJcub127 · #8 12-15-2010, 08:46 AM

Quote:

Originally Posted by B-Brush

Just my 2 cents but if you try to unscrew that fuel nozzle your askin for trouble it is very easily stripped and hard to find a new one best bet is to soak it in one of those cans of carb cleaner you can get it at your local auto parts for around 20 bucks

don't take this out. I just had to replace that piece in my carb because the Prev owner must have tried and messed it all up. I had to use a easy out and a drill to remove it. I did get a new one for $15 but why waste the money if you don't have too.....

cumminsjeep · #9 12-16-2010, 10:01 AM

My way of getting around the gummed up/ corroded/ issues with the old carbs is to first remove as much as I can (fittings,choke plate, throttle plate, maybe the inlet valve, or the main jet) WITHOUT forcing it.Then I dunk the sucker for a couple of days in carb cleaner. Then I pull it out (wearing thick rubber gloves) hose it down, blow it out with compressed air. THEN remove the remaining parts. On the throttle shaft/ choke plate screw issue, I have procured a pile of 3-48x3/16(?) ( I think that is the correct length) SHCS (socket-head-cap-screws) These work really well and are reusable. Just a tad of locktite 242(?) to hold them in place, and you are good to go. Yes, the heads may cause a little extra turbulence...... big deal. serviceable, runs great.