[chaiya]

Anyone have any advise on removing a stuck / broken screw on my carb? While trying to “fix” my bike…husband broke off the head of the pilot screw (sets the air/fuel mixture). He took the carb off the bike and tried to drill it out, but was unsuccessful. Do you think heating it may help? Anything else I can do? Time to shop for a new carb?
My bike looks really sad all taken apart

[SantaCruzRider]

Not sure what the issue was with drilling, but usual cause of failure is not having the correct drill bit (need one for metal, not wood), starting with a bit too large or otherwise trying to drill on a surface that causes the bit to wander).

I’ve found success with the following method:
1. Go to the local hardware store and buy a screw-extractor. It’s basically a spiral bit that digs deeper as it’s turned counterclockwise.
2. Back at the bike, heat the screw up a little and then spray it with WD40 or some other penetrating oil.
3. Centerpunch a small divot in the center of the screw shaft — this will help provide a start for the drill bit. (You can probably use a thick nail for this.)
4. Start with a very small drill bit made for drilling metal and create a starter hole — (Metal drill bits are meant to cut slowly — so keep your drill on a slow speed. This also helps avoid breaking the bit off in the screw!)
5. Follow with a drill bit that matches the size indicated on the screw-extractor you bought — again, drill slowly.
6. Now insert the extractor and slowly extract the dead screw.

Best of luck

[chaiya]

thanks for your suggestions!

He was using some kind of screw-extractor set. He bought it from sears just for this. It is a very tiny brass screw.. it is threaded for about half a cm then goes to a point. He just couldn’t get the screw to move.
will try heating and the WD40

Hoping this works…

If not, I’m hoping for a new carb as a chanukkah present …

[SantaCruzRider]

Since it’s brass, and fairly soft, you might try drilling it out with a bit that is almost as large as the screws.

One thing I’ve done before is to start small and use progressively smaller bits. You might end up with what is basically a hollow shell of a screw. You can then use a small flathead screw driver and needlenose pliers to pull out the remaining parts of the screw. If you’re lucky, you’ll still have decent theads left on the carb.

[SantaCruzRider]

Sorry, must have been typing too fast

[Munch]

Only caution with heat….. make sure there are no soft plastics in the vicinity of proposed heated area. I know your thinking “well …duh!” . I am a mechanic and trust me…. I fix more of the “well …duh!” situations then I should. As SC said start small and work up … the last thing you wanna do is mis judge the size of the screw and end up boring out the threads of the hole.
Let us know if ya get it…. if not I can look back in some of my tricks….like…mild heat and candle wax…… don’t laugh…. saved many a engine head that way.

Yesterday is a memory, tomorrow is a prediction, but today…… is a Bi**h

[chaiya]

candle wax?? kinky….

so what do you do with the candle wax?
any other tricks?

thank you!

[megaspaz]

Please… this is a family friendly site!

—
If there’s anything more important than my ego
around, I want it caught and shot now…

[Munch]

Lol…the candle wax trick is fairly simple…. but only if you can manage to get to the bolt, screw, nut whatever have ya. If you can, try to get a notch in the stripped piece… via a screw driver or whatever…. heat the screw up fairly hot…. take a candle stick and press it on the screw….the wax will melt and since its a thin liquid will seep into the threaded areas….once it cools down it acts as a lubricant in between the threads. Doesn’t always work but usually for me does better then PB blaster or WD40. If you have to use a Phillips ( + ) head then use that to tap the notches into the top of the screw. being its brass it shouldn’t take much.
Question….ok …..your fairly sure the screw is brass or just has that color……..and what is the body made of?

Yesterday is a memory, tomorrow is a prediction, but today…… is a Bi**h

[Author]

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