a few KDX questions

I don't think there is amything that can make this bike very loud. They are a quiet bike by nature. Most people never have problems with deep water crossing after airbox lid removal. I never have, although I never put it through water that goes to my seat. Respringing the forks works miracles, I wish I had never waited to do mine. A rev pipe will probably help you out, with a minimal loss on the bottom. The 220's aren't really revvers, but can be modded fairly easy to gain a little over rev. Have fun on the new toy.

If you wanted to rev, you should have gone with the 200. The 220 was introduced to provide more low end torque. To that end it is easily enhanced. A K35 pipe, turbine core II silencer, torque ring, boyesen 607 reeds, airbox cover removal, wiseco piston(do it now before you regret it!!!) lean the jetting out(wait until after break in period), drop a tooth on the counter shaft sprocket, add flywheel weight. With these mods, you will have a hard time stalling and you can go anywhere in third gear while your buds on 200's are shifting madly between 1st, 2nd, and 3rd, trying to stay on top of their power curve. Lot's of things can be done with the forks. Check out Jeff Fedette's site at www.frpoffroad.com for revalving and springs or go the route I did and add KX125 forks.

Try the RB carb mod discussed here on the forum. They bore it and put in a plate to mimic the 220's small bore but when you open it up (since it has been bored) it will give you the high revs you are after. I think it costs around $165 or so to get done. It's worth a look! :)
http://www.rb-designs.com/kdx200-220.htm

Although I am fairly new here myself, it would appear from canadian daves 200 vs 220 tests that the 220 can be made to rev quite well and still keep the low end. Check it out.

mmersol- I looked all over his site... can't find that test..... Do you have a link? Thanks! :)

Thanks Kev!

Rather than removing the air box lid I'd recommend grabbing your drill and adding a number of holes to the lid. A 3/4 inch spade bit works well. You'll also want to remove the snorkel. If you are worried about elevated noise levels you should know that modifying the air box lid will allow you to hear more noise being emitted from the carb area.

I'd highly recommend installing heavier fork springs to bring the bike back into balance front to rear. The handling is greatly improved and much more confidence inspiring. Respringing is dependant on your weight but typically most riders will retain the stock 5.0kg/mm shock spring and replace the stock fork springs (0.35kg/mm) with a set of 0.38 to 0.40 kg/mm units. I'm about 170lbs and tried both 0.38 and 0.40kg/mm fork springs and found the 0.40 units allowed the bike to track straighter in rutted sections etc.

Your observation about the top end power falling flat is a common one. The first thing I'd recommend doing is to add an FMF Rev pipe. FMF has just changed their part numbers but I can tell you the old model number was KG-30. Avoid the KG-35 (torque) pipe with your 220 if you're looking for more over rev. It falls flat on top just like the stock pipe. You'll notice a little more noise being emitted from the pipe but nothing very meaningful. The stock silencer does a good job at keeping the noise levels down but unfortunately it’s on the heavy side. The FMF TurbineII is a quite after market silencer and is only slightly noisier than the stock unit. The KG-30 will add considerable power to the mid and up with only slight improvement to the bottom end power. Your stock 33mm carb will certainly work well with after market exhaust but having your carb bored to 35 or 36mm will result in better mid to top end power with only a slight loss in bottom end throttle response. The RB carb mods work well and deliver the best of both worlds. As an added bonus most find the larger 35 to 36mm carb easier to jet than the smaller 33mm carb.

Be sure to go through the new bike prep article on the JustKDX web page paying particular attention to the section on greasing suspension linkage.

If you're going to use your KDX like a sub then yes you'll want to retain the stock lid in unmodified form. If you'll be doing modest water crossings though there's nothing to worry about. 1 or 2 feet of water with a modified box isn't going to be a problem.

Enjoy your new bike

David

All of CDave's mods are a must, and I'd like to add the a Delta Force II reed cage will help retain the bottom end w/ the KG-30 and RB carb.

A riding partner has this setup and it will pull from idling in 3rd (almost stalling) to overrev nicely! Makes for an awesome powerplant!

I was worried a little about water in the airbox too, so I left the lid on, the snorkel in-place, and drilled two one inch holes, with a spade drill, in the rear of the airbox lid. One in each corner behind the snorkel. I cut two pieces of 1 inch O.D. aluminum tubing (Home Depot) about 1.3 inches long and stuck them in the holes. Nice tight fit. I actually used my lathe and made a shallow groove in each tube so they snapped in place when pushed into the plastic lid. You could do this too with a file and some patience if you don't have access to a lathe. The tubes stick up about .5 inch or so and clear the frame when putting the lid back on. By my calculations, this increased the flow area by 50%, and there is room for another between the first two if necessary, and more room up front!
I don't know how much the flow area should be increased before it's enough, but after reading this forum for a while it's clear that increasing it is a good thing. This mod is clean, preserves the watertight intent of the airbox lid and snorkel, and significantly increases inlet flow area.