Motorcycle Repair: sick yamaha fz1, yamaha fz1, vacuum leak

Question
2004 fz1 ran flawlessly for 5k.fouled plugs on first start of day,full choke 70 degrees.Plugs very wet and black,replaced plugs worked fine for awhile.Would foul plugs on occasion,got worse,tried to start it one day and it even backfired loudly.Another website suggested incorrectly adjusted fuel mixture screws.Any idea where that is on the carb and what the proper adjustment is,thanks for your help,jim

Answer
Hi Jim,

Sorry for the delay. I'm working out of town this week.

I suspect the problem may be a vacuum leak. Possibly a hose off or defective.

Otherwise, if the engine starts and runs with choke, but stalls without choke, indicates varnished pilot circuits in carbs.

Check out the links on this website:
www.angelfire.com/ia/z/FZ1sitemap.htm


Respectfully,
Mark Shively