Make sure it is 10-40 oil you put in. I had 10-30 in my x, the clutch slipped from 3/4ths throttle and up. Put some 10-40 in and now it doesn't even slip. Mine needs a new bore and piston but it seemed like it smoked less now because of the 10-40. My x is an 84 and it is almost as close to running parts you can have. Thats going to change soon hopefully
current rides
84 200x - being rebuilt-supertrapp exhaust, uni air filter, hopefully a 10.5 to 1 piston
84 big red - cobra exhaust, custom head lights
83 185s - 200e engine, cobra exhaust
82 yz 60 - engine is out supposedly needs piston and rings