Stripped mixture screw bs34 removal and replacement?

[section8joe]

Ok, got my bike running and I needed to jet it. The previous owner must have drilled out caps(bs34) and filled them with silicone. I pulled out the silicone and the right mixture screwhead is completely mashed up. How can I get it out? I don't have an easy out small enough to fit into the hole. Once it's out how can I replace it with this? Part #48-5011 http://www.mikesxs.net/products-37.html#products

 

[Ghetto]

Once you get it out that is indeed the correct part you need for replacement.

 

[weekendrider]

You can slice down the middle of the tower with a cutting wheel and "reslot" the screw.

 

[gggGary]

I have cut down the tower and reslotted the head with a Dremel cut off wheel. Xjmx reported success reslotting the head with a small burr bit in a Dremel. He did not have to cut the tower. It is always a good idea to use a rust buster on stuck threads. Once you have the slot recut you need to have the carb either clamped in a vice or supported so it is stable so you can get above a properly sized (grind if you need to, to get a snug fit) flat blade screw driver firmly in the slot then with plenty of down force turn the jet. The idea is NOT to bugger the slot again you will not get a third chance. With skill and luck you will hear and feel a "tink" as the jet unbinds and begins to turn. It has worked for me and another member just reported success with this technique a few weeks ago.
If the reslot fails then you drill and easy-out might try drilling the jet with a LH bit. On a beyond hope carb I tried to drill and easy-out, it didn't work, after several tries the jet head expanded and the carb body broke at the thread. It happens, there is a poster in classifieds looking for a RH body today. The PO split and tried to JB weld the body.

 

[xjwmx]

The one that I got out with a burr on a Dremel I had to reslot several times. It was reslot, get a quarter turn before it stripped, and repeat a few times. It was stuck that badly. Finally it got loose and came out. I got a replacement needle from a local garage with some parts carbs around.

 

[section8joe]

I never closed this thread. I got my pilot out with a left handed drill bit.

 

[gggGary]

That's a great answer S8J I don't think an easy-out should be tried on these.

Here is the what has worked for me now and it doesn't ugly up the carb body. I used the busted body to help show how I did it.







The tool is some stainless from a car windshield wiper blade ground to make a "tooth". The idea is to carefully deepen and reform the slot so a screw driver can be used to back out the jet. The stainless easily cuts curls of brass off the screw. Compressed air, applications of rust buster, and reading glasses all help. You need to get the carb set firmly so you can get down pressure on the screw driver to fully engage the new slot you have formed. Watch that you don't dig "too wide" and get into the threads on the body.

 

[xjwmx]

When I did the one I was talking about I used a cylindrical burr like a dental burr, not a wheel. Didn't have to cut down the tower first. When you do this, expect a V rather than a precise slot, but it's good enough if you go easy. And smaller burr rather than larger...

 

[gggGary]

Just a random use of a LH bit, I broke off a sheet metal screw in a plastic cell phone mount. That's a 1/16" drill bit... if you are careful (and lucky) you can drill the center of a very small screw. Plastic was very tough but once the screw got hot from drilling it backed right out, Part saved.