spitting and sputering

[speedracer400]

hey buddy has a z400 and not quite sure wut all is done to it he just bought off some kid. when he first got it the fan switch was bad and when the bike got warm it would spit and sutter. he replaced it and it was fine for couple wks. now donig the same thing. any ideas?

[HondaRacer300ex]

I didn't really understand your post but I have a stock radiator for sale if that helps.

Also, what sputters? The fan or the quad?

[speedracer400]

the motor sputters any time you stab the gas but only under aload. it idles fine. he has run probably 2 tanks of gas thru it since hes had it only 93. when the prob started it would run good until it warmed up. then he would jump the fan switch and it would be fine which is why he replaced the the fan switch. it was fine up until the other nite it started again. know jumpingthe switch won't stop it. nothing else on the bike has been messed with. are aftermarket cdi boxesa prob ?

[ltz400rider118]

I would clean the carb and check the valve clearances to be sure they are good (2-6 intake and 8-12 exhaust). If it still does it then try a different cdi unit.

[speedracer400]

thanks thats about wut i told him to try just sucks cuz were suppose to ride today. he only paid 1000 for it so

[rrguy]

Could be the stater clutch bolts coming loose. Sounds like it. Pull off the flywheel cover & check. If it was running fine now all of a sudden is missing, that would be my guess.

[roperr]

Sounds familar. Once it got to the stator, it was all over!!