Motorcycle Repair: 1972 Yamaha AT1 throttle/carb question, cause havoc, tiny particles

Question
Hi Michael - I'm trying to get an old '72 AT1 going again after 20 years of sitting in a basement.  I can get it started but the throttle seems stuck wide open and I have to quickly shut it off using the key.  I'm unsure of how to troubleshoot this problem.  Thanks in advance for any help.

Answer
Lee,
 The slide may be stuck open, you should be able to feel it by the loose action of the throttle.  Sounds like you may have to do a breakdown of the carburator and make the crucial adjustments and clean it correctly.  If you are comfortable in making these repairs you should consult a good aftermarket manual like "Clymer" or "Haynes".  These will walk you through it and give you the proper tolorances and measurements for your particular model.  Often if carburator is left with fuel in it, the fuel eventually evaporates and leaves a varnish like substance that siezes and blocks crucial parts.  Here is some info I've given others on this process:
Disassemble, clean all jets and orifaces with solvent and COMPRESSED AIR ONLY, use NO wire or picks to clean holes/airways. Rebuild carbs with new gaskets and make sure your floats are set correctly. . Do not overlook the float level, be very sure you are not starving for fuel. In relation make sure fuel flow is unobstructed and use a good in-line fuel filter from the tank to the carb. Even tiny particles in the fuel can get logged in critical areas and cause havoc.

Mike