Page 1 of 1

difficulty with jetting a 220

Posted: 08:18 pm Jun 16 2009
by 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.

:sad: i'm desperate

Posted: 09:16 am Jun 17 2009
by 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.

Posted: 09:36 am Jun 17 2009
by 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

Posted: 02:40 pm Jun 21 2009
by 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

Posted: 10:06 am Jun 22 2009
by fuzzy
Have you tried a leaner pilot?

Verify KIPS working?

Posted: 10:54 pm Jun 22 2009
by 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

Posted: 10:55 pm Jun 22 2009
by kevfort19
how can i do to see if the kips i working ok?

Posted: 04:07 pm Jun 27 2009
by 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

Posted: 07:45 pm Jun 29 2009
by kevfort19
somebody have something for me???

Posted: 12:15 pm Jun 30 2009
by 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...

Posted: 06:31 pm Jun 30 2009
by kevfort19
thanks i will try this , i will buy a 38 pilot jet

Posted: 05:57 pm Jul 05 2009
by 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

Posted: 04:37 pm Jul 14 2009
by kevfort19
i receive my JD jetting kit, so i will try these needle and jet

Posted: 11:32 pm Jul 21 2009
by 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.

Posted: 09:26 am Jul 22 2009
by fuzzy
There you go! :mrgreen: