Carb Rebuilds & Impact Drivers - My thoughts

[Wingsconsin]

On almost every carb rebuild thread I read through there is a moment when the one or another carb screw / fasteners is too stuck and stripped to be removed. Often advice is given to use an IMPACT DRIVER to get is loosened. This process makes me extremely nervous as we are dealing with aluminum carb bodies and steel fasteners.

The culprit is generally a mismatch in tools. If you are attacking Japanese screws with a standard Phillips screwdriver you will eventually strip them out. The Japanese bikes are JIS screws (Japanese Industrial Standard) and are different....Google and buy a set of these and realize how easy it is to get a good grip when you have the proper tool

Further - if the screw is stripped out -- why add IMPACT FORCE to a carb body that is precious. The idea and common practice is to get NEW FASTENERS (usually Allen head socket) so the old ones only need to come OUT and get tossed into the trash...

I suggest you look to your local Sears Hardware and get a set of Craftsmen Deck Out screw & bolt removers. About $20. They fit in your drill and run in reverse. You use the appropriate size tool and 1 end is a flatened like bit that forms an indentation into the top of the fastener..then you flip it over and the reverse therads grab the fastener and -zip - out it comes to be tossed away...

No risk of IMPACT to crack or damage other parts.....and it works just fine as I can attest having used it on several fasteners over several bikes I have refreshed these past couple of years...

[GateKeeper]

Great information, but the tool you post does not always work.....

That is the reason one gets an impact driver and the proper JIS bit and out they come...

or you use a dremel cut a slot in the screw and use a flat head screwdriver

one typically needs an arsenal of tools when working on most things that are 30 years old...

.

[spchips]

I use impact drivers all the time, haven't cracked one carb yet. there is minimal force on the carb if it is properly supported in a vice with wood, or just with a piece of wood under to support the carbs, depending on location.

You need the good one from NAPA or snap-on, etc.

[Nessism]

Carb bodies are zinc, not aluminum. Never had a problem using an an impact driver.

[steveb922]

I believe carb bodies are MAZAC (or possibly ZAMAC in the States). An alloy of zinc, magnesium, alumin(i)um and copper.

[Wingsconsin]

The need to be specific and exacting is interesting ...
All I know is that this tool set has not failed me yet, and gotten out 2 screws that were stuck beyond any other resource ...including an attempt to use the impact driver.
In the interest of disclosure ..The carb bodies are more fragile than I would like to hammer on regardless of their composition .

[spchips]

An impact driver requires its own zen. I'll grant that in the wrong hands it is more destructive than helpful. However i'm sure the same can be said for the extractor tool.

Also, i have to admit that i cracked my first carb body today. Just a hairline, but still a crack. The top of the late 80s kaw carbs had extremely thin material on the top cover, and it cracked. I should have looked at what was doing. will try covering with thin epoxy to stop the air leak.

The gs carbs have much more material on top. This never would happen with them or most others.

[bomber737]

I use sears electric impact driver. 1350 in/lb's of force. Works great with JIS bits. No chance of braking carb body and it works 95% of the time the first time. I keep a set of vice grips handy to turn those stubborn screw heads. Most of the time I wind up only using screw extractors to get the butterfly valve screws out when they are messed up. Left turning drill bits are also helpful to have around

[Katarat]

Only time Ive used an impact driver is on screws that go into the steel rail that holds the carbs together, those babies are tight ! I have JIS screw drivers and they wont budge them. This aint my first hay ride either.

[steveb922]

Only time Ive used an impact driver is on screws that go into the steel rail that holds the carbs together, those babies are tight !

Suzuki (or Mikuni) used the Japanese version of Loctite when these were built - heat is your friend here.

[mrbill5491]

I have used a drill bit to just drill off the top of the screw head when it was buggered up. Once you take what ever it is off, the tension on the screw is gone and they come out nice and easy.

[spyug]

Another method taught me by a pro m/c mechanic is to take a "cold' chisel or flat bladed screwdriver and hold it to the head of the screw at about a 30 deg. angle in the direction of loosening. One good whack will generally loosen it but will gouge the head.

Once the screws are out I would suggest replacing with cap screws for an easier time when you next need to rebuild.

[tkent02]

A little cordless impact works great for these. Zip zip zip done. Can get an entire rack apart in about a minute. Doesn't hurt the screws if you want to use them again.

Once in a while the screws in the rail take a bit more impact. Usually not.

[bobgroger]

+1 for the cordless impact. The only screw I couldn't get out was a carb boot screw, the head stripped and needed a chisel....Otherwise it has worked great. I have a Ryobi, was $99 with a drill and 2 batteries.

[gs11ezrydr]

I agree with others with the cordless impacts, a small chisel at times at the right angle has worked for stubborn or already stripped screws, I have a set of these Vampliers that I use often as long as there is access to get to them. They actually work pretty good and can be used on anything really. Might want to check them out. http://www.vampiretools.com/.