difficulty with jetting a 220

[kevfort19]

i'm trying to jet properly my KDX because at low rpm, it don't have a good sound and have no power. I'm currently 42, r1173L, second clip from the top, main 145 at 750 ft and around 75 degree.

Can anyone help me, the when i try the jetting guide, i start with the airscrew and the rpm never go up. My idle screw is all the way in and my bike have a very slow idle.

i'm desperate

[Colorado Mike]

It sounds to me like the pilot circuit has a problem. The idle screw should work. Take the carb off and look in the throat and make sure it's really moving the slide. if not, maybe it's the wrong screw. Float level should be set and carb squaeky clean before messing with the jets.

[kevfort19]

the carb is clean, the idle screw work a little but it is fully screw in. to set the pilot circuit i have to screw in the idle screw to make the idle fastest. but it is already screw in. When i unscrew it, after one turn the bike stop.

I will tcheck if the screw is good. i tcheck my float level and it is to 16mm, so no problem for this.

remember that my airscrew do anything, even if i do 4 turn out, but when i turn fully in the bike stop

[kevfort19]

the idle screw is ok, the float level is okay. i change my main jet for a 142 instead of a 145 and the bike goes better but at low rpm i don't have power

[fuzzy]

Have you tried a leaner pilot?

Verify KIPS working?

[kevfort19]

i trie a 40 instead of a 42, and its the same thing the idle screw do the same thing and when i turn the airscrew the rpm never goes up

[kevfort19]

how can i do to see if the kips i working ok?

[kevfort19]

So i check the KIPS and all is working
i forget to tell you that I foul plug.
When i ride in trail at low rpm the plug comes very spoogy,and after a long times in trail the bike start to miss fire and after this...it is the dead of the plug. but i do a plug chop test on a long way at full trottle and check the plug and it was dry and dark brown

[kevfort19]

somebody have something for me???

[fuzzy]

When i ride in trail at low rpm the plug comes very spoogy

Could try going leaner on the pilot yet. like trying a 38? Can't blow your motor with small changes in the pilot like this. You'll know when it's too lean...when you wack the gas under load it will cut out, then pick up. Also, adjust the air screw! OUT is LEAN. out to two turns or so before changing pilot to next leaner size, then always start at 1turn out when testing new pilot and adjust from there.

Could be ignition related too (weak). Does it break up in the high rpm at all?

Carb could be wearing out.

Also, test for air leaks around the carb/boot with carb cleaner while the engine is running....it will run different if it sucks some in. This generally results in high, pulsey idle though...

[kevfort19]

thanks i will try this , i will buy a 38 pilot jet

[kevfort19]

i'm waiting for a JD jetting kit for kdx220 , and i take the compression of the bike and the compression is OK so i wait the jets

[kevfort19]

i receive my JD jetting kit, so i will try these needle and jet

[kevfort19]

I had intalled my Jd jetting Kit on My 220, it increase the trottle response and give a little bit more power. I'm very happy.

[fuzzy]

There you go!