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So here's my dilemma. I have a 1987 KDX 200. Im running a DG pipe and silencer, a set of Boyesen Pro Series reeds and the cylinder was ported and replated by Jeff Fredette and if anyone cares it has the blue inverted forks off a 1992 KX 125 sprung to my weight a rebuilt rear shock also sprung to my weight ( took some serious effort to find the rear shock) those are all the mods.

I can't get the jetting right. I'ts easier to ask for help with the jetting for this set up than to explain which ways and how many times I got it wrong. Any help would be greatly appreciated. Ive dreamed about this bike since I was 16 and I just need to figure this out. Thanks.

Check the jetting section for the sticky on how to jet. Nobody can really recommend you settings based on the mods you've made, as every bike, every rider, and every climate has different requirements. I'm also going to move this out of the RB Mods section and into the jetting section.

Do you have the stock carburetor?

Which jets are in there now?

I have the stock carb. I'm running the main jet 2 over and the pilot is stock. The needle is set in the middle. I't has no power at low rpm's and it breaks up as it climbs. It starts first kick every time (took 2 kicks after the rebuild) no knocks or pings, the power valve is quiet as well so im confident it's mechanically sound. My concern at this point is screwing up the cylinder by running it to much with jetting being off. As for where I ride, Mountains , normal trails to mud pits and occasionally going out for an 80's race at a motocross track. Except for the mountains most of the riding is between 10 and 400 feet above sea level.

Is there another carb besides the flat slide off the 88' model? That was something I was considering. It's a better carb for sure , but how noticeable would the improvement be? I appreciate the help.

Have you tried a different pilot or have you always just used the stock size?

The trick on the 1986 - 1988 on carbs is the choke lever on the right side.

What is the plug you are running? What does its color tell you?

My thought was to go up 1 on the pilot. I am running a stock pilot jet. I started with a NGK B8ES and the plug read lean. Fear of over heating made me switch to the stock NGK B7ES and thats a little rich. I thought of going down to a 1 size over stock main jet but not sure what to do on the pilot. What do you have to do with the choke lever?

Standard plug is a 9, isn't it?

7 is even hotter. Most other carbs have access from the left side, unlike the 1986 - 1988 KDX200

yes your right. I do have a 9 i it right now.

forget "just change the jet size up/down x many" and use the jetting guide.

it walks you through each circuit (pilot vs main), needle clip, air screw, one at a time, and is very easy to do. then you can record a summer and winter setting, then change them very easily throughout the year.

i won't ever go back to guessing sizes again, after learning from it.

http://www.kdxrider.net/forums/viewtopic.php?t=1156

that's the guide

Thank you. I'll check it out now.

If you have the stock carb, there is no air screw.

im willing to change the carb but I'm not sure which way to go. I'm looking to squeeze as much as possible out of the old gal.

Get an '88 carb or buy one that you can make the switch on for the choke lever.

Thats what i thought you might say. Ive searched for a year with no luck. It may be asking a lot but ,If you happen to know where i might locate one that would complete the bike.

FRP Offroad used to have old bikes he parted out.

thanks ill check it out.