Just had my 98 ZL500 carbs cleaned and Synced. B4 that my sled rna beautifully for 1100 mile this season. After I got it back the thing ran great for 10 minutes that started to bog. After just flooring the gas it would go but it then started backfiring out the exhaust. Had this problem on and off for about 40 miles. The next 40 were wonderful. Disconnected the safety switch on the throttle but that didn't help. to boot I can't shut the thing off with the kill switch or key.... Help

bypass the electric magnet switches on the carb's see if this takes care of your problem i had a zrt600 doing the same thing i found out the switch on the carb was shorting out.

Pilots made be clogged check those..G