joe_zrt

i have a carb zr500 and it seems to be runnng off of one cylinder. it starts off fine but won't get past 7000rpm and barely hits 50mph at full throttle. has new cdi box and just replaced piston and rings and it still runs like crap. sometimes it seems to come on both cylinders and pop up to 8000rpm but falls right back down to 7000rpm could it be a coil or something else. i'm stuck.

1000ml

pull your plugs and see if one is wet . if it is the coil breaking down the plug should be soaked in gas.try swapping carbs from side to side and see if the problem switches cylinders. also swap plug leads from one to the other to see if problem follows. have you pulled the carbs apart to make sure there is no ice or dirt caught in the jets?