mixture screws stuck - how to remove them

[R-Tru-D2]

Tearing down my carbs for cleaning and replacing some O-Rings. The metal plugs hadn't been drilled out on my GS1100GK carbs, so I did the deed myself. Carb #4 mixture screw came out very easily and I was able to replace the o-rings without trouble. The other screws are stuck in place. I got a couple of them to turn a little bit, but they're pretty much stuck in place. I have the carbs on a bench vise, and I'm using a good screwdriver, but there's no turning these babies in either direction. I pretty well stripped one of the screws, so that'll make it that much more difficult to remove.

Heck, maybe I should just leave them all alone and not worry about it, but it just bugs me to not be able to replace their o-rings now that I have everything all torn down. Any help removing stuck screws? I already tried PB Blaster and let them soak for a bit - no luck.

[dgeorge]

This was posted by arveejay a while back, it might work for you.

OK, maybe some of you know this but I didn't so I'm sharing it. I have seen carbs that have sat for many years ruined because screws would strip out rather than come out, especially airscrews. After I drilled out the plugs on a set of carbs for a 650 this weekend and before attempting to remove them I decided to try something a little differant. I took the heat gun and heated up the area areound the airscrews real well, hot to touch, then filled each hole with liquid wrench and let them soak for about an hour. The screws almost removed themselves, not really, but they came out just like they were just put in last week. I'm assuming heating the housing allowed the liquid wrench to run down the threads as it axpanded and allowed them to come out extremely easy. This is the only way I will ever remove them from now on. Try it you'll never do it another way.

If this doesn't work for you I would take them to a machine shop and have them drill them out. I had to have one done and they only charged me $5 for it and didn't even have to retap the threads on it. Hope this helps with yours.

[KEITH KRAUSE]

The heat gun idea sounds good. The factory puts a sealant on the threads, so the heat can help break the sealants hold. Also, the carb body probably expands quicker than the brass screw.
Unless the o-rings were leaking, you probably should have left them alone. But I know you just wanted to do a complete job.
If you did'nt move them too much, you're probably OK. After you test ride, you'll find out. Good luck.

[Anonymous]

Same problem here, went to tear down a set of carbs for a 1979 GS1000L, and one of the setscrews would turn in both directions, but would get stuck when trying to remove it. I took some penetrating oil and let it soak in, with no noticeable effect. The screw started out damaged, but I made it worse.. I managed to extract it with the help of a $5.00 Micro-torch from the local auto-parts store.. (judging by the flame the micro-torch puts out, a standard torch-flame lighter should also do the trick, but it might get too hot and melt).. I applied the heat, and then extracted the screw with a little effort due to the damage.. Now, I just need to find a new setscrew, so I can finish the cleanup and adjustment. most of the o-rings in the carbs were beyond shot, so the job is long overdue...

[arveejay]

Here's a little secret I just found out, if you have a drill press. Make sure carb is level and flat, a drill press vise works excellent, chuck up a 1/8 in drive high quality bit into drill. While using the pressure of the drill press as you are pulling the handle down, grab the chuck in the other hand and back out the screw. With pressure from the drill press it's near impossible for the bit to slip. I also have taken a file to my bit to make the sides more square to the surface. Most bits are tapered which allows them to climb and slip, if you file the bit flat at the edges it will bite the slot much better. When I discovered this I dug out some old carbs which I had given up on and tried it. They came out using this method. Remember these carbs are aluminum and too much pressure may strip the threadsif not allowed to back out..