black exhaust/ jetting question

[larrk2300]

2001 kdx220 fmf kb35 pipe, fmf turbine core II silencer, air box lid removed, uni air filter, PA woods riding, waterpumper oil 32-1 94 pumpgas. where do i start to jet carb. it seems to blow lots of black oil and seems a little rich. shouldnt it be lean with new pipe? thanks ahead

 

[fatty_k]

Do plug checks at various throttle positions. Where abouts in the RPM range do you usually ride within? That may be your culprit circuit. I find I ride mostly low-mid rpm's so if there is spooge out the silencer, I will lean out the pilot and raise the clip position. First, do plug checks with a new plug and go from there.

 

[larrk2300]

i put in brand new plug today and pulled not any sign of fouling i ride low to mid range throttle, anyone know what stock jets come with 220 service manual and fmf site dont agree. also my air screw was out five turns, i reset to 2 1/2 but we are getting storm i cant tell diffrence yet

 

[fatty_k]

5 turns out!! If you find it runs best at more than 2 turns out, install the next leaner pilot. I would try a leaner pilot for sure, and maybe raise the clip position one. The stock pilot jet is 42 I believe, so I would recommend running a 40 pilot or maybe even a 38. I run a 40 with ok results, but I may try a 38 soon. The stock main jet is a 145. I went leaner on the pilot (40) and richer on the main (150). With needle in #2 position, and I play with the air screw daily.

 

[larrk2300]

ill dig into carb tomorrow. thanks for starting point, are the jets fairly easy to find at bike shops i havent checked, also does anyone elses kickstarter hit the fmf pipe? also my pipe bolted and lined up perfectly, i was surprised from what ive read.

 

[andrew]

Yep, my kickstart used to hit my FMF rev pipe, until I rotated it on the shaft one spline to the rear...

 

[larrk2300]

thanx for the help, relocated kick starter perfect.

 

[canyncarvr]

5 turns out?

Is your 'air screw' black?

For basic jetting info and changes to that for basic mods, go to CDave's site:

http://justkdx.dirtrider.net

 

[larrk2300]

thank you everyonr i went with 40 pilot, 150 main, one clip position up, 1 1/2 turns out. runs perfect, now i got to get tire to stop spinning on all this hardpack we have this dry summer.