Motorcycle Repair: 1987 kawasaki ke100, kawasaki ke100, cause havoc

Question
This bike has not been run in about 14 years.We changed the 2stroke oil, cleaned the carb, gas tank, points and magneto(quite a bit of rust),and changed the spark plug & air filter. Now when I try to start it, it gets good spark but if it starts it will only run a few seconds and then backfire out the tailpipe or carb. and die. Any suggestions?

Answer
Bret,
Sounds like you may be dealing with a fuel delivery problem. If there is a malfuntion in the ignition system is is usually more abrubt, sudden or total failure. Typically you won't get a coil with poor resistance to succesfully sustain a running engine. It either will run or it won't, sometimes relating to changes in the coil's tempature (heat increases resistance). If you're concerned about the resistance rating on your kawi's coil, check and compare it to the reccomended allowable resistance (stock or aftermarket manual). To rule out other ignition related flaws examine and adjust points(probably not an issue since I think your model may have a solid state ignition), timing is critical. Check for loose or corroded connections which could cause sporatic failure. Make sure you have a strong blue spark upon crank over.

  It is very possible you have a malfuntioning carburator. You may have contaminants and/or varnish on critical parts. It is also possible your choke is malfuntioning. I can't go into all the specifics and tolerances but here is some guidance on cleaning carbs I've given others (I highly suggest getting yourself the manual for reference):

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. Floats are suppossed to push the valve up into it's seat when they rise from the fuel. Sometimes they get debris around them or varnish up with old dried fuel and get stuck either open or closed.

Hope this helps,
mike