I've got an xt350 which miss fires or jumps roughly between 6 and 8 thousand revs ,worse when hot .i`ve cleaned and checked the carb and seems to be fine ,fitted a new plug cap and new coil still no change .Running out of ideas can anyone help.

When you let the throttle off a bit it runs sweet.

Tumbleweed...........................

If you want some good advice then you need to go here for info......http://www.thumpertalk.com/forum/9-yamaha/

I have a 1986 xt350. What year is yours?

hes not been here since january!