KDXRIDER.NET

Ok, this Jetting thing is getting to be a pain in the #%& and costly. I have a 2000 KDX 200 with a FMF woods pipe, turbin core 2, brand new boisen torque reeds, air box lid opened up, run 32:1 golden spectro with 92 octane. I live / ride between 1500 ft and sea level. I have read Indas jetting guide (thank you inda) and went to a 45 pilot, raised the needle one clip and gone up to a 165 main. the power is there from the bottom to about 3/4 throttle but seems to run out of rpms quickly at full throttle. While doing the plug chop I get the cleanest whitest plug you could imagine. the bike has about 135 psi of compression, brand new no toil air filter and the silencer was just repacked. there has been no "mods" done to the engine. How high of a main jet are you guys using, i see most of you are running alot lower. I have to stop by the bike shop tomarrow to get a few bigger jets.

Try a 155 Main and a 42 pilot... air screw out 1.5 turns out and the clip in the second slot on the needle.

You should never go above a 155 on the main IMO.

your plug chop shows a very faint band with a 165?
maybe you have an air leak somewhere in the system?

I checked for air leaks around the carb, reeds, ect. none. it seems that if the crank seals were leaking i would have some oil comsumption in the gear box. ?
I have the needle in the second slot from the bottom (raising the needle) and with the 45 pilot I am between 1 1/4 and 1 3/4 turns out depending on weather.
during normal riding the plug seems to stay about brown, not tan and not black. but the lack of top end and the seeming to be lean has me thinking to go bigger with the main.???

Have you actually cut the threads off the plug so you can see the entire
porcelain ??
I'm with Inda on the starting point 155-42
That 165 should give you a dripping wet fouled plug with in minutes
How about a plugged main circuit or a float level set to large ?

I feel kinda stupid now. I pulled the fuel tank valve to find that it was pluged up some. tried it again and got a black plug. So the shut off was acting like the main. I got the jetting down to 155 / 42 and it seems to go pretty good now.

Inda, when you say "clip in the second slot on the needle" is it the second from the top or bottom?

Second from the top....

Sweet....Good job figureing it out!

I was just out playin with what i got and it seems to bog in the second clip from the bottom. I am going to try to go all the way to the bottom but the jack ass that put the needle holder in the last time (me) must have been nervous about it falling out and I pretty much wrecked it geting it out. Is there another needle to try or am I missing some thing else. (In my defence I am a heavy equipment mechanic, I work on diesels not carberators for a living.) It dose seem to be pretty good for the most part on the bottom and top now but if you go from 1/4 or so to 3/4 it dose seem to bog. but not every time ether

Did you mess with the air screw? Usually a 1/4 turn will take your bog away....

I have not had a good chance to really play with it for an extended time. I get home from work late and only have about an hour to play with it during the week at night and if it will run it will get rode on the weekends. I will try the air screw some more. Thanks alot for the help.

hey rbates! i know your pain man...i also have a 2000 KDX motor in my hybrid with a PC platinum pipe and FMF powercore 2 silencer..iv been tinkering with jetting for a while now and i finally figured it out...although im only about 100ft above sea level..im running a 42 pilot with a 158 main and clip set in the middle of the needle..air screw is about 1 and 3/4 turns out...every bike is different when it comes to jetting but it might give you somethin to try! also...look at Inda's jetting guide..it really helped me out good luck!

Thanks, I ended up with a 155 and 42 with the clip all the way down and finally just said f&%# it. It wasn't fouling plugs and it was acting alright so I moved on to other things. Might get back to it in a while. But at the time I had enough and let it go.

keep in mind w/ record heat this summer - this might not be the right time to be testing jetting IMO LOL. I just went thru w/ what you had to deal with and decided to quit riding until the temps drop below 90 average high.

2nd hottest summer on record! SUCKS to be a two stroke lol....

BTW my jetting w/ a bored 36.5 mm carb, PC works pipe and open airbox is 155 and a 42 pilot. I am also running a DEL needle, which is fat.
Seems the consensus here that this is probably the richest jetting required.
I am just gonna slap my airbox lid when it gets cooler until it's too cold to ride (in the south, that's January and February ;) ......)