when i feather the throttle a low rpms the engine sputters & sometime stalls or pops
i cant lug the motor at all ????
full yoshi exh,160-165 main jets 25 pilots,open airbox + k&n
top clip on the needle

 

Try putting the clip on the third groove of your needle. 2 turns out on your idle screws.

 

Definately move the clip down, which effectively richens up mid range. Start with the 3rd notch from the top with no lid.....and test.

 

Yup I agree, low end stalling due to hard hesitation is a lean condition. I 've had that a problem a few times when the weather/temp changes & I cured it with richening the fuel screws. At least 3 turns out each is a good place to start. I got tired of playing with the fuel screws so I installed 25 pilots & leave screws around 3 turns each in winter, maybe 2.5-2.75 in summer. I also noticed the Rappy likes the clip up higher since most airbox mods actually richen the low/middle end due to slower air velocity. Too much air gives great mid/top end but causes low end air velocity/turbulence. I run with the clip on pos 2 or 3 depending on temp/weather.

 

after the weather change the past few weeks my bike has leaned out considerably try needle adjustments


BRAAAAp

 

Mine used to do the exact same thing so I raised the idle just a hair and problem solved. There was an article in ATV Sport or something other than DW talking about people blowing the carb boots off. The main causes were a lean condition, not warming up the engine properly, and last but not least, too low of an idle. I tried the latter and never had a problem since.

 

I 2nd this.