KDX220 rebuild time

[Terminatr]

Hi,

just bought a KDX220 2003 from a guy who said he bought the bike a few years ago and as far as he knows it's never had a rebuild. The bike looks like it's been ridden a lot. It seems to run fine, but I'm not familiar with these bikes. I've never ridden anything this powerful before. Also, the bike seems to kick start fine, and I felt a good bit of compression from the kick starter. I ride trail solo, can't afford a break down deep in the forest. Should I play it safe and rebuild the engine?

-First time smoker owner

[SS109]

If it has a stock piston I would replace it ASAP! They are known for the skirts breaking and trashing the engine. If the plating looks good then I would probably just add a new Wiseco piston, rings, clean the KIPS, and new top end gaskets and go have fun. Go factory Kawasaki on the base and head gaskets. The KDX bottom is tough and I highly doubt it needs a rebuild.

[Terminatr]

Thanks for the info. I guess I'll get a manual and open up the engine. Never done that before on a bike, but have a lot of experience on cars. Is there a internet site for buying factory Kawi parts? I just hate driving into town to the Kawi dealership. I prefer parts mailed to my home.

[SS109]

I have used Service Honda (Yes, Honda!) with great success. Good prices and good customer service. The ThumperTalk store is supposed to be pretty good as well. I haven't tried them yet as I'm one of those guys that when I find a good place I tend to stick with them.

[Tribey]

Hi, I did the same to my recently acquired Y2000 220.

The Kawasaki service manuals were shown as 'out of stock' at my local (UK) Kawasaki dealer. You'll need the 200 manual and 220 supplement, but I went for the Cyclepedia option.

The top end break down is quite straight forward, I put some paint spots on the KIPS valve assembly just to make sure I got it all back as it should be. The Cyclepedia manual is quite vague on this aspect.

I heeded the warnings and put in a Wiseco piston, although the stock one looked OK, and the bike appeared to have been well used by previous owners. The riding in my area is varied narrow trails, but with very little flat out areas, meaning the engine doesn't spend much time pinned wide open.

I also fitted a new air filter, re-packed the silencer and, with a full FMF pipe already fitted, went down on the standard 145 main to 140 to try to cure the mid to wide open bogging. It started first kick and runs really good, but I don't know what I changed to make this difference, or a combination.

My only problem was the nut at the top of the KIPS actuating rod (I should have realised it was now actually a bolt not a nut). There are plenty of forum warnings, and a marking on the claw, to tell you it's a clockwise to undo thread, so with this in mind, I undid it clockwise. It seemed very tight, when it doesn't have to do much holding, so shouldn't be. Then it snapped off! Checking the broken bolt revealed it had a normal thread and the top of the rod had been re-tapped with traditional tread. So it appears a previous owner might not have headed the warnings and broke the original stud and replaced it with standard bolt. I re-tapped the rod, and again re-fitted a stand bolt, and painted a new arrow on the claw. I must remember to tell the next owner when I sell.

Good luck.

[gsa102]

Look at the bolts on top and at the base of the cylinder for wrench marks. If it has them it may have been taken apart already and possibly rebuilt. That would be the only indicator. The KDX engines last a long time, so age isn't reliable.

Was the PO the first owner or the second?

It might be a good idea to do it just so you know your piston won't grenade. You can find a manual on KDXrider.net

[Terminatr]

The PO was at least the second owner. He bought it used.

I removed the expansion chamber and peeked into the exhaust port. I see very little blow-by on the piston. So, I'm going to wait a while before opening the engine up. There're many other more pressing issues with this bike. Looks like the PO didn't do much regular maintenance.

Is the stock piston really that weak? I don't race or anything close to it. I do mostly tight single track trails. On my XR200, I mostly lug the engine on 3rd. I don't plan to run the KDX hard. I'm old enough to be scared of getting hurt. Just don't heal as fast as I used to. I do things conservatively. Little kids on their XR80 pass me.

The front bear is totally bad. And the fork feels a wee bit rough. I guess I'll do the fork & bearing first.

[SS109]

Is the stock piston really that weak? I don't race or anything close to it.

The stock piston is a weird thing. You can run it for 10 years and never have a problem. Or, you could start a brand new bike and the piston skirt would shatter. It doesn't matter how hard you ride, what jetting you run, nothing. They are just prone to coming apart with no warning and for no reason. You can run the stock piston but don't be shocked when you trash your top end or, even worse, your complete engine!

[Terminatr]

Hi,

I have another question. It's about shocks. I've read somewhere my '01 KDX220 came with unbalanced suspension, meaning the front is good for a 150-lb rider but the rear is good for a 180-pounder. And it was recommended to replace the springs to suit the rider. I'm about 150-lb. My question is that for just typical tight trail riding, would I notice much difference with a new rear 150-lb spring. I don't race.

[asg5265]

the forks work well, but yes you will need to put a new spring on the shock if you want the bike to work better

[OLHILLBILLY]

Buddy of mine has an '05 220, took the cylinder off and found the piston skirt had 2 cracks in it, with about 1/4" left before the cracks came together.

Top ends are easy on 2 strokes. Get 'er done..

[asg5265]

^^^testament to why you check it...

[slaydirt]

my KDX220 head gasket went bad shortly after i got it,bought a gasket kit and figured id check the piston and clean the kips,my bike is a 98' and had the stock piston in it,my bike doesnt have a ton of hours on it though im the 3rd owner.the stock piston had no cracks but had alot of carbon build up on top,changed my reeds and replaced all the gaskets and o-rings other than splitting the cases.my bike straight rips now,so as you can see its like SS109 says you just never know with the stock piston,better to just change it and have peace of mind!!!!