I put the stock piston back in my quad after it over heated and broke my 11/1 cp piston. with the cp I was running a big gun, with a 185 main jet and 4th clip down on the needle, ran great! but now with the stock piston in it, it runs like crap in the midrange. the spark plugs look white-light gray.

whats going on?

 

Dyna jet or Mikuni?

 

mikini

 

With just a pipe I would say 172.5 to 175 main jet and 4th or 5th groove groove on the needle.

 

Also 3 to 3 1/2 turns on the mixture screw.

 

counting down or up the needle?

 

Would say down!![img]i/expressions/face-icon-small-smile.gif[/img]

 

Down from the top.