KDX220R said:
Just bought stock 2002 kdx220R
How should it be jetted ? It has good low end power, but the throttle from 1/2 to full doesn't seem to pull the bike any. Cleaned filter,stock silencer-blue gunk out, new plug, 32:1 synthetic oil-gas mix, and it appears to using alot of gas--tank lasts 35 miles or more --but running tight technical trails.
Engine sounds strong and no popping some at smoke at idle.
Should I change jets from the stock set-up? Beginning rider don't know if i'm ready for the expense of the hop-up mods--pipes/silencer, etc. Would like to proceed slowly to make this bike a killer performer, i.e. growup with it.
Did you buy it used? Are you sure it's jetted stock? Stock jetting in the 05 model is: 42 slow jet; 145 main with the needle set (dead center) 3rd clip with the airbox lid in place. This jetting is very rich.
I just bought a 05 KDX220. One freebie mod you can make is remove the air box lid under the seat. Relocate the CDI. I relocated mine in the air box on the right upper corner. Then go ride it you will notice quite a bit more over rev (top end). But you may lose a lot of the bottom end. Also you might try a 40:1 fuel mix.
Next step:
Drop the needle in your carb to the 2nd or 1st clip from the top.
to regain the bottom end.
Or install a #40 slow jet and adjust your air screw. Leave needle on the 3rd clip and ride it. If it is still blubbery down low change the needle to the 2nd clip and adjust air screw.
This is the first KDX I have ever owned and I have found everything is a compromise. To gain bottom end you lose top end performance. To gain top end you lose bottom performance.
I have made almost all the bolt on mods to mine (pipe and reeds) and have found that I could have made the stock pipe perform almost as well. You just have to fiddle with the jetting and air box lid to get what you want out of the bike. I have never been able to equal the low end power of a bone stock bike with the after market stuff. The low end pull has been the most disappointing part of the bike. I have had a lot of fun with the bike so far and am having fun fine tuning it. You will be able to grow with the bike. I weigh 250+ lbs and the bike can rip with me on it.
Don't be fooled with all the hype about the add on pipes. You will be surprised at what the stock pipe has to offer. The aftermarket reeds are a nice mod which is relatively cheap. Each mod adds a bit more but most are adding top end at the expense of the bottom. I should have played with the stock set up more before I started buying stuff.