Motorcycle Repair: hondacb750k4, air screw, panka

Question
Hi Mark
I'm having a hard time starting the bike.
I have to pull choke all the way out and lock it . the next step is to tern  the thumbs screw counter clock wise  2 revaluation. start and rev. Once started i have to adjust thumbs air screw to keep at least 1100 rpm s .  Let the bike worm up and blam , the r.p.m s go from 1100 to 3000, all by it self.  then i tern down the thumbs air screw clock wise to get 1100 r.p.m s.   This is getting old .  i would like to fix . I have the clymer service book but, but would like something a little more helpful .
                                     thanks steve.

Answer
I can be fairly sure your pilot jets are clogged. The fuel that sits in the carburator eventually will harden or "gum up". The pilot jets have very very small inlets which let a very small amount of fuel into the carb at idle to 1/4 throttle. 9.9 times out of 10 this is the case.
Unfortunately, the only real cure is to remove the carbs, remove the pilot jets (usually inside of a very small tube once the carb is turned upside down, easily seen with a flashlight) And to run compressed air or a very small wire. One strand from a small parts brush works very well otherwise if you intend on doing this often, a set of jet drills can be picked up for around $40.00.

Hope this helps!

~Mark Panka