Idle mixture screw won't come out!!!

[Cobia]

Hi,
Been cleaning the carbs on the '79F, which came with the series 3 instead of the originals, and found that the idle mixture screw on carb #2 is nearly impossible to remove. I've soaked with PB Blaster, Liquid Wrench, you name it, from both sides and have been able to back it out to about 1/4" from the top of the tube. But the screwdriver slot is about to give it up and I don't want to do more damage to it before getting suggestions.
It make me work quite hard for the progress so far. And contrary to what you would expect, it would not screw back down more that 1 to 1 1/2 turns before binding again. I was expecting to be able to screw it back down along the "progress route" but it would have none of it. I think it was cross-threaded in and thus the current situation.
btw - these are the dirtiest carbs I've ever encountered.
Any one run into this situation?
I'm considering cutting the top 1/4" to 1/2" off the "tower" it screws into to get access to it with a pair of small vice grips. I did some comparisons with the other "towers" and noticed that this would not compromise the threads. The head slot is now almost gone too. I would need to grind down a screwdriver to attain proper hold on the head, no big deal but it's not giving it up!!
Should I just drill it out and replace it? Are they available?
Any and all ideas are welcome.
Thanks

[Ken Talbot]

Use a fine diamond burr in a Dremel tool to reshape the slot in the screw.



Be careful when you're down inside the tower to keep your machining to the brass screw, not the aluminum carb body.

[Cobia]

I hear you Ken...
Looks as if I'm going to visit my local dentist soon.
With the bleeder in the cailper and now this, I'm going to need a source of these burrs!!

[CatatonicBug]

Wouldn't an easy-out work? I just went to lowes and got the smallest (#1) easy-out they had for about $4.00 to remove the old pilot jets from my carbs. It worked like a charm.

Of course, that is assuming you have a replacement screw to put back in there once you get this old one out.

[tarzan]

I had to drill one out this summer on a friends SG.It was a pita.I ended up putting it in a mill and using an endmill to cut a hole on center, then drilled it out to the minor diameter.I had to peel the threads out with a dental pick.Very tedious ,but it worked.
Yours at least sounds like it moved quite a bit.You are right that you can cut the top of the tube around the screw to try and get a vise-grip on it.
If you have to drill it out be very carefull to get the drill on center.It is easy to mess up the threads in the aluminum.

[cywelchjr]

Wouldn't an easy-out work? I just went to lowes and got the smallest (#1) easy-out they had for about $4.00 to remove the old pilot jets from my carbs. It worked like a charm.

Of course, that is assuming you have a replacement screw to put back in there once you get this old one out.

Model 3 carb mixture screws are available from MikesXS. They come with the spring, o-ring and washer.

[Radiation]

my experience

I had the same thing happen to me. I just kept loosening and tightening until it finally came out. It took me almost a full weekend to work it out and I mangled the slot on top pretty bad. When I finally got it out I reslotted it with a dremal and emery wheel. I went to the local Yamaha dealship to order another one. There is no part number for it, so they couldn't order it. They spent over an hour looking. My modified one worked fine until I found a thread on here that told me about a site the had the complete setup(screw, spring, washer and o-ring) for only $6. I ordered 4 sets and replaced them all and kept the 3 good old sets for spares. They worked like a charm.
Here is the link:
https://www.carbkitscapital.com/carb...a&model=XS1100
Thank you Topcat for saving the day... AGAIN!

[latexeses]

If the carb is free of gas you might try a pencil torch or a torch cigar lighter to heat the carb body. If it is crud it might free it up enough to remove. If it cross threaded it might expand the aluminum just enough to get it loose.
Just a thought...

Rodger

[Cobia]

All great suggestions

Looks as if I'm going to get me a burr to re-slot the head for a good grip with the screwdriver, apply some heat to the tower and see what happens.
And thanks for the link on where to find a replacement also.
I'm going to avoid drilling it like the plague but if I have to......
I'll keep you posted.
Thanks again!!

[Ken Talbot]

I hear you Ken...
Looks as if I'm going to visit my local dentist soon.
With the bleeder in the cailper and now this, I'm going to need a source of these burrs!!

Lee Valley in Canada sells an economy set of burrs that might be your answer.

[Ivan]

My 81 has had the mixture screw "tubes" cut down considerably. At some point a PO decided to cut the tubes down instead of drilling out the aluminum plugs. One of them is cut down a half inch or more.

If the appearance isnt an issue to you, just take a dremel cut off wheel and cut a new slot in the screw after removing some of the tube.

[Cobia]

Ivan,
Appaerance is always an issue but since the bike is intended as a fix and sell item, my main concern is to get it going ASAP.
That will be my next step if heat does not do the trick.
Thanks.

[Cobia]

Success!!!!!


Rode up to Harbor Freight (nice day to ride) got the diamond burr points. Re-slotted the head of the iddle screw, applied heat to the tower (after protecting the choke area with thick aluminium tape) and after a little coaxing it came right out. Hip, hip, hurray!!!
I just ordered a new set of them from Carbcapital.
Thanks all for your tips, suggestions, and encouragement. I'll keep you posted on the progress.
Bikerphil and I should have it running by Saturday afternoon!!!
Gracias, Amigos!!

[Cobia]

Busted a main jet....

After removing the idle screw and cleaning the carbs I went to work on the re-assembly. And wouldn't you know it, when I screwed in the first main I forgot the washer. So I took it out inserted the washer and in the first turn of screwing the main in, it broke just above the threads. And nooooo, it wasn't cross-threaded, just weak. Thank heavens for easy outs. Went to HD to buy the right one and the remaining part of the main came out while I was checking for a fit!!!
Bikerphil came over this morning with some 125 mains and after adjusting the floats (and several other sundry tasks), we installed the carbs and it fired right up. It required minimal synchronization and with the 125s it goes like a bat out of hell!!
THANKS PHIL!!!
Yet, all's not well in paradise.....
2nd gear is toast, it skips when you lay the power on. So.......DGXSER, I hope I'll be as lucky as you were with your repair.
Wish me luck guys and gals.
Thanks

[ossjughead]

are the idle mix screws the same in a xs as a xj if not does anyone know of a place i can get some i had to drill 2 out and would like to buy 2 sets for both bikes

thanks Jim