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2005 KDX220. Got my cylinder back from Langcourt. They matched it with a Wiseco piston kit. Got everything installed. Added Boyesen power reeds. Added Pro Circuit platinum 2 pipe and spark arrestor/silencer. With the old piston/rings, pipe, reeds the low end was not all that great but when the power came on it accelerated like a banshee. Now it has tons of low end power but falls pretty quickly. I find my self shifting gears often because it won't wind out. Luckily the low end is so good it pulls pretty good when I'm in a gear too high. Question is: Where do I start for jetting changes? I'm thinking moving the jet needle a notch maybe? Also, I didn't vent the airbox. Would drilling a couple of 1" holes make a difference? Thanks in advance yall.

I don't have specific advice for ya because I haven't done much with my jetting either, but you can start here

http://www.kdxrider.net/forums/viewtopi ... 105&t=1156

for some good guidance. Good luck. Let us know what you do and how it works.

Excellent! Thanks.

My 220 has great bottom end/mid range pull but falls flat on top too, its just the way the 220s were designed to be due to the porting...you can remove the snorkle ( keep the lid on ) & like me drill x3 holes near the snorkle opening & install `uni filters` for a little extra air..if you want to wake the bike up a little more then fit the 35mm carb off the kdx 200 , once you`ve dialled in the jetting ,it will help in the mid range & upper end of the rev range without any sacrafice in the low end pull that the 220s are known for ..a worthy mod for a 220.

cornishwrecker220 wrote:My 220 has great bottom end/mid range pull but falls flat on top too, its just the way the 220s were designed to be due to the porting...you can remove the snorkle ( keep the lid on ) & like me drill x3 holes near the snorkle opening & install `uni filters` for a little extra air..if you want to wake the bike up a little more then fit the 35mm carb off the kdx 200 , once you`ve dialled in the jetting ,it will help in the mid range & upper end of the rev range without any sacrafice in the low end pull that the 220s are known for ..a worthy mod for a 220.

After the changes I've made I've lost a lot of my midrange. It hits a wall where it used to keep accelerating. I forgot to mention that I changed the main jet to a 155. It had a 152. I did this because I didn't want it to run lean after installing the new pipe. It's a case of changing too many things at once. Somebody suggested that I install the boyesen power reeds without the original reed holder (including v-block). Hmmmm.

i think i was running a 142 or 145 in my 220 before the carb swop with the needle in the 2nd from top position, this was with the air box mod, fmf gnarley pipe & boyesen rad valve with reeds with a 40.1 fuel/oil mix....if you want to dial in your jetting then i would first re-pack the silencer (unless new) ,install a clean air filter, fit a new spark plug & fill up with a fresh fuel/oil mix before you start tweeking.

cornishwrecker220 wrote:i think i was running a 142 or 145 in my 220 before the carb swop with the needle in the 2nd from top position, this was with the air box mod, fmf gnarley pipe & boyesen rad valve with reeds with a 40.1 fuel/oil mix....if you want to dial in your jetting then i would first re-pack the silencer (unless new) ,install a clean air filter, fit a new spark plug & fill up with a fresh fuel/oil mix before you start tweeking.

I haven't drilled out the airbox yet. Will do that first thing. The silencer is new...also new air filter, plug and fresh gas. Fortunately carburetor changes are easy. I just have to be patient and change one thing a a time.

go 4 a ride then do a plug inspection..it sounds like its running on the rich side & wouldnt surprise me if it smokes alot too on full chat..put the needle clip 2nd from the top & see what thats like for starters then go down 1 size at a time on the main till it rides/pulls clean...a fat main will effect the fueling over the whole rpm range & not just on full chat...i recon your main should be around the 145/148 mark given your mods.

I just did all the exact same mods. A 155 main jet seems to rich 145 is stock. The boysed reeds will make it run slightly richer. I am running a 148 Main. 38 Pilot. I have great low end and top end. I couldn't believe the difference the pipe and reeds made.

When I first got my 220 it had the same issue. Good low end but it felt like it hit a wall around 6k rpm. The previous owner had rebuilt the top end recently. Bike has fmf torque pipe and spark arrestor, boysen reeds, no air box cover. Long story short the power valve wasn't opening due too a tweaked actuator rod and the sub valves on the wrong sides of the jug. With power valve fixed, bike ran great! Switched to a 142 main and it ran even better! Hope this helps

150 anything sounds wayy too rich for a 220. Wasn't 220 stock jetting something like 145 / 42? You will almost certainly end up leaner than that. Definitely double check your power valve anytime you are having power issues, but in this case, sounds like we need to start with the jetting.