Motorcycle Repair: 1981 Honda z50, fuel tank, varnish

Question
Hi I have a 1981 Honda z50 and ive had it since the beginning of the summer.  It ran great all summer, then in the beginning of september I had it confiscated because i was riding it without a license.  It is now september 28, I got it back about a week ago, and now it does not run good at all.  I can kickstart it, and it will run for a few seconds, backfire, and stop. Sometimes I cant even get it to start.  I have done everything i can think of, ie. checking the timing, ignition gap, valve adjust, carb clean, feul, air flow etc.  But it still will not run.  Please help me!! Thanks!!!
Cam

Answer
Smell the fuel in the fuel tank.  Does it smell kind of like varnish?  If so, you you may just need to drain the fuel out and replace with fresh.  As fuel ages the lighter elements evaporate and the fuel won't burn as well.  So it fouls plugs and causes the symptoms you describe.

Regards
Rich