my scrambler 400 runs poorly between1/8 to 1/3 throttle
i have a 30 pilot jet 1/2 clip spacer on the needle and 260 main (hpdpipe/airboxmod)
plug check is black and wet between 1/8 to 1/3 ( idles good)
runs great from1/2 to full shoud i raise the jet needle or go with a 25 pilot

 

a sputtering might be a lean conditions or an dirty air filter,might be
a clutch setup defunct sometime,but i guess you should try to raise needle clip one notch cauze it is exactly there it start to influences
the jetting a lot.did you tried to play with the fuel screw to richen the
circuit?

 

airfilters good
i have not tryed playing with the air screw yet
seemed to be rich
thanks for your imput.

 

If it appears to be rich at that throttle position you lower the needle not raise it.

You move the clip up one notch and that lowers the needle.

Also polaris slide needles and nozzles tend to wear quickly. You may need to replace them.

 

i remover the 1/2 clip spacer running better (not perfect)
clip is 2nd from bottom afraid to go much leaner
260 main rich enough? not room to test it
should i go with a 270?

 

Do not remove the spacer. That useally makes them far too lean.

 

the 1/2 clip washer came with the jet kit and was recommended by hpd for the pipe/airboxmod
idid not remove the stockspacer sorry for not making that clear
the clip is still in the stock spot
plug check is darkbrown
thanks for the help cornbread2

 

When I piped my bike I ended up going to the second from the top position. That cleared up the stumbling and it ran great. If you do change it be sure to do a plug check.

 

The second from top should be about right no matter if you changed the pipe or not.

 

Also this is a 2002? If so about how many miles?

It most likely needs a new slide needle and nozzle.