KDXRIDER.NET

I currently own a 1996 kdx200 that I bought that has a totally rebuilt top end, fmf exhaust and the rest is stock. Currently, I am having trouble finding what to do about the jetting. I need some suggestions on needle position and jetting for a 45-50 degrees F mild Michigan winter and 200 feet above sea level. Right now, everything is set for 60-80 degree weather but it's lean at the moment so it's bogging out and I don't want to cease it. Any suggestions on how to make it run right?

What's your jetting now? What position is the clip on needle? How is it running now?

Trial and error my friend, there's plenty of information on this topic (search this site and or Google). No one can tell you the best set up for your bike as your bike will ultimately tell you once you jetted it correctly. A good starting point at least for me (located in PA) was 42 pilot and 150 main with the needle in middle position. Others may have started elsewhere, this was good for my bike. Once you get started, the plug will need pulled to inspect color. Once a light brown coat is reached (on the porcelain of the spark plug), and feel of bike operation. You have found your jets.

Mario

Go through the jetting guide found on this site to get your setup dialed in.

MarioM3 wrote:What's your jetting now? What position is the clip on needle? How is it running now?

Trial and error my friend, there's plenty of information on this topic (search this site and or Google). No one can tell you the best set up for your bike as your bike will ultimately tell you once you jetted it correctly. A good starting point at least for me (located in PA) was 42 pilot and 150 main with the needle in middle position. Others may have started elsewhere, this was good for my bike. Once you get started, the plug will need pulled to inspect color. Once a light brown coat is reached (on the porcelain of the spark plug), and feel of bike operation. You have found your jets.

Mario

I literally just bought the bike and haven't gotten around to tearing it appart to see. I came to the forums to see some suggestions, the bike runs great though. It idles well even in the 10 degree weather I bought it in. It turns over on 4 kicks at a dead cold start. I tried to test ride it and that was a fail, it bogged to the point where it almost stalled. That's when the guy told me it was jetted for warm weather (60+ degrees) but didn't know what the jets were. I was seeing if the needle can be adjusted to compensate or tweak the air just to get me through the weekend when the temp goes up to 45-50 deg.

Sounds more fuel related than jetting. Switch the flow valve on reserve instead of on. How's the gas look? Maybe tap the float, sounds more like fuel to me at this time. Taking off the carb and checking/cleaning jets isn't hard and takes very little time. While your in there I would check over the float and set it to 16-17mm. Also fresh gas will probably be good idle.

Mario

MarioM3 wrote:Sounds more fuel related than jetting. Switch the flow valve on reserve instead of on. How's the gas look? Maybe tap the float, sounds more like fuel to me at this time. Taking off the carb and checking/cleaning jets isn't hard and takes very little time. While your in there I would check over the float and set it to 16-17mm. Also fresh gas will probably be good idle.

Mario

Gas is brand new 93 oct with ethanol stabil and amsoil 2 stroke. I have it at 44:1 per previous owner. And ok I'll have to investigate the float. I have the service manual but any places of reference for carb cleaning?

It's straight forward. I use 3M carb/throttle cleaner (comes from work so its cheap for me) but its actually very good stuff. You can use any, any parts store will have some. Remove needle/jets, inspect, clean. When installing jets once there snug there tight (brass will break easily) so don't go Hercules on them. Make sure the slide is clean, inspect for damage. Now the float is what you need to really look at while inspecting (in the manual they have pictures of what to look for). When I get home I'll take a picture if needed.

Mario

Just a warning about carb cleaning, do NOT soak it in Chemdip or use brake clean on it. There is a rubber seal that is not normally removed and if you soak it or use brake clean it can destroy this seal. Then, no matter what you try you'll never get it jetted correctly until you replace it.

SS109 wrote:Just a warning about carb cleaning, do NOT soak it in Chemdip or use brake clean on it. There is a rubber seal that is not normally removed and if you soak it or use brake clean it can destroy this seal. Then, no matter what you try you'll never get it jetted correctly until you replace it.

Good point. The gasket is question is the jet block gasket.

Given the age of the bike, this gasket may be knackered anyway, so it might not be a bad idea to go ahead and order 1 or 2 of these little guys ($4.41 each) and plan on a full scale carb cleaning.

Davenay67 wrote:

SS109 wrote:Just a warning about carb cleaning, do NOT soak it in Chemdip or use brake clean on it. There is a rubber seal that is not normally removed and if you soak it or use brake clean it can destroy this seal. Then, no matter what you try you'll never get it jetted correctly until you replace it.

Good point. The gasket is question is the jet block gasket.

Given the age of the bike, this gasket may be knackered anyway, so it might not be a bad idea to go ahead and order 1 or 2 of these little guys ($4.41 each) and plan on a full scale carb cleaning.

Yup. That would be the smart thing to do.

Thanks guys, I was able to see the jets were lean so I changed them to what Fredette suggested for me and the rest was up to spec. The reeds were a little stained so I'm replacing them and it should be good to go! It was really easy and I didn't dip the parts, I cleaned it will my hands and a little elbow grease. Much appreciation! Side note, the float needle. I noticed when you push the needle rod nothing pops out like the manual said. I figure that's normal?

Davenay67 wrote:

SS109 wrote:Just a warning about carb cleaning, do NOT soak it in Chemdip or use brake clean on it. There is a rubber seal that is not normally removed and if you soak it or use brake clean it can destroy this seal. Then, no matter what you try you'll never get it jetted correctly until you replace it.

Good point. The gasket is question is the jet block gasket.

Given the age of the bike, this gasket may be knackered anyway, so it might not be a bad idea to go ahead and order 1 or 2 of these little guys ($4.41 each) and plan on a full scale carb cleaning.

I recently ordered a new jet block gasket. I have a friend with the special torx bits. Is there anything special I need to know before disassembly?

Sent from my SM-G900V using Tapatalk

19Delta wrote:I recently ordered a new jet block gasket. I have a friend with the special torx bits. Is there anything special I need to know before disassembly?

Not really. Just keep everything clean and orderly.