Serious carb Issue, carb gurus please look!!

First off Im new to the board but not new to VFR's or wrenching. I have owned a few VFR,s and absolutely love them and always recommend them.

So I'm working on a 1995 VFR750, I have cleaned the carbs thoroughly and they look great but I have a big problem that may make them useless. The tip of the mixture screw broke off on the front two carb, I have never seen this in my 25 yrs of wrenching. Now most i4 carbs you can see the tip in the throat of the carb body but not in these beauties. So my plan is to put some compressed air on the other side of the needle and blast it out. The three small holes in the throught are not allowing enough air so I was looking at this brass plug at the bottom of the air mixture tube pictured below. Can this be removed and replaced? My plan is drill a hole, put a screw in it, add head and pull it out. Apply compressed air to shoot the mixture screw tip out with 160psi, then brase the hole I drilled and replace the plug with sealer, jb weld or the like. I need to know if the plug will give me access to the rear of the mixture tip? Remember these are worth nothing the way they are.

Thanks for the help,
Tim

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So the screw was removed but just the non threaded portion of the tip is stuck? You got a picture of how much of it was removed?

 

This is what I have with the remainder of the right needle stuck in the metering hole.

 

Here's some ideas of what i would try.

Spray some berrymans B12 carb cleaner in the exit port to loosen up any varnish.

Poke a steel guitar string down the exit hole of the mixture port to push on that tip piece.

Replace the pilot jet and plug it up with a toothpick, plug up the pilot air jet with a toothpick, tape over the 3 transfer ports, then apply air pressure into the mixture port exit hole to try to force the tip out.

Put it in an ultrasonic cleaner or some kind of vibratory shaking device.

Chance are it was broken off by overtightening, so the tip piece is shoved down into the taper so far that it distorted the carb body. Even if you get it out a new needle may not ever work properly if the tip orifice has been damaged--it's a very dimensionally critical orifice.

Good Luck let us know what works out for ya...

That brass plug covers the access hole they used to drill out the 3 transfer ports and you can remove it like you described--may want to try to heat the aluminum carb body to 300 - 400 F before the pulling to make it easier to pull out. If you don't drill all the way thru you can reuse it--just drill deep enough to put 3 or 4 threads of your pulling screw.

 

I doubt compressed air is gonna get it done, do you have a welder with a bottle of gas? Thinking maybe some aggressive solvent into the port and monkey a line onto the brass fitting from some high pressure compressed gas and see if it wont shoot the little bastard oot. May have to think ootside the box to seal up the bleed port but if you can get some real pressure behind it and some wicked solvent in there and let it sit for a bit.......

 

Tough one, Tepco, hope you get it fixed. I agree with K-B that the area where the needle seats is probably ruined.