Stan's 1990 KDX200

[stansama]

Hey all! I started an intro thread a few days ago and thought I might keep posting there to keep things simple, but then I thought I might add a lot more pictures eventually and have more questions, anyway I figured I should start a thread in the E series forum and get a little more personal!

For those that missed it, my name is Stan, I grew up in Maine on an island off the coast of Camden/Rockport area. I've been riding on two wheels since I got my first bicycle, and I think I got my first dirtbike around 10 or 11 but I can't remember for the life of me what it was back then (17 years ago). From there it was up to motorcycles, started with my mom's Honda Rebel before I got my permit and license, then I got my own Ninja 500. In college I picked up an 05 GSXR750 that I traded three years later for my current car, and last year I found an 04 CBR 600RR for a good deal that I snatched up.

About four years ago I picked up this KDX when I had some extra money and wanted to have a little fun. It ran ok for a while and I eventually lost time and interest and it sat for a while. Now I'm interested again and have time, so I've been working on giving it some life again. I'm going to paste the pictures I put in the intro so I can have everything here in one place:



I apologize, all of these pictures are done with my ipod it's all I have :/ Anyway, that was before teardown. Discovered this beautiful looking piston:




Unfortunately the cylinder had been scored, so I hemmed and hawed about it until I finally sent it off to powerseal usa for a replate. $381 later I have this (would have been closer to 320, but they found a crack that needed welding):




Annnnd....



A new wiseco piston :D So I'm super pumped about that. I wish I had done a before and after of the cylinder, it blew me away when it arrived and looked brand new!
I still need to order some parts to get going. I was planning to remove the engine and get the crank seals done as I believe they are leaking a tiny bit, but I've run out of money at this point. During my struggle to get the engine out I had to saw the swingarm pivot bolt off, here's the result:



Bearing had seized to the bolt, what a pain that was to remove! Took me a few days of cursing and trying different methods, but I finally prevailed.



This is the left exhaust valve, three of the teeth have stripped so that needs to be replaced. The right side one is fine, so that's good. I have a question about the center valve, it has two teeth on it that look shorter than the others, almost as if they had been stripped but the edges are smooth, unlike the broken teeth of the left powervalve which are sharp. Here's a picture:



Is it supposed to be this way? From what I can tell the powervalve rod never even reaches this spot?
Two more questions and I think that's it for now, phew! Do these reeds look ok? Probably hard to tell from the pictures, but there's no cracking or splintering anywhere, just looks like one side has burn marks on it?




I had put up a question in the introduction regarding the kickstarter spring, but I've gone ahead and added it to my order along with a host of other parts that I needed. I hope this will fix the problem of the kickstarter failing to engage sometimes. The last question I had was concerning the swingarm bearings, but I think I've discovered that answer as well. I'm going to try cutting a slit in the sleeves and hope they come out, as all my pounding with a sledge has got me nowhere.
Anyway that's it for now! Happy riding all.

[KDXGarage]

The middle KIPS valve does engage on the teeth.

[Julien D]

The notch or cutout in the teeth on that center valve are so that you can install or remove the rod and then the center valve. I think your center valve is ok.

[bufftester]

Center valve is ok, as Julien said, its that way to aid removal of the actuating rod since you can't remove the center valve with the cylinder on and the engine on the bike. For the bearing shell in the swingarm have you tried putting heat on the outside of the swingarm? Just like installing them, heat the swingarm, freeze the bearings (only in this case no freezing) The pivot hole should have no ridges in it, so likely its the remains of the cage. If your swingarm bearings were this bad you REALLY need to check the linkage bearings...ICRage will be happy to show you why They are probably the most neglected and abused bearings on the bike, and if the swingarm was that bad

[KDXGarage]

It can get ugly!

[stansama]

Thanks guys, no I haven't tried heat yet as I don't have a torch, but I'm going to try the method of cutting a slit in the sleeve first since I do have a dremel, sawzall, and hacksaw. If for some reason they're still stuck after that I'll see about buying/borrowing a torch. Is it necessary to heat the swingarm prior to installation of new bearings, or would just freezing them do the trick? Surprisingly the linkage bearings look great, I believe the previous owner must have serviced them but neglected the swingarm bearings for some reason (maybe the bearings were already seized by then and he said F it?) I'm still awaiting new parts in the mail, in the meantime I've got the powervalve parts soaking in kerosene to get them cleaned up.

[bufftester]

It's not necessary to heat/freeze, but it sure makes the job a whole lot easier, the bearings just drop right in like butter. When I did my linkages recently I just popped the bearings in the freezer for a couple hours and didn't use any heat and they slid right in. Same for doing case bearings, linkages, etc...but don't use a torch, get a 20$ heat gun from Home Depot or Ace...lots safer and you'll find lots of uses for it (Especially up there in Maine...I spent a long winter there years ago at Loring Air Base in Caribou bbrrrr).
Good news on the linkage. For slitting the cage, just use a hacksaw blade and score it by hand carefully, then you should be able to get a screwdriver blade under it and pry it right out.

[stansama]

Well I haven't had the chance to get to the swingarm yet, I've been working on the car and motorcycle and my buddy's Toyota. Just got my parts order in the mail and tomorrow looks to be fairly open so I should be able to get some work done! I've had the powervalve assembly soaking in kerosene for a week or so and I'm going to take a toothbrush to those tomorrow and get em cleaned up. Will this work on the cylinder head also? I didn't get a picture, but I'm sure you can guess what it looks like judging from the top of the piston.
The new spring I got for the kickstarter doesn't seem to have more tension than the old one, but it's hard to tell, I suppose just a little bit could make a difference. Here's hoping it works!
I think I have everything to put it back together now. Any tips/tricks that would be helpful for putting the top end back together? It seems fairly straightforward, but I've never installed a piston so I'm not sure what to expect. I have the service manual so I should be all set, man am I pumped to get back on this thing!

[diymirage]

what i always do when i install a piston is make sure i oil the inside of the cylinder
liberally
place the cylinder on the work bench upside down (the cylinder, not the bench)
then i take the piston and install one of the circlip and push the wristpin into the other side
i put a little bit of oil around the top of the piston, line up the rings with the locator pins in the grooves and compress the top ring
(most 2 stroke bikes ive found thos can be done by hand if you line the piston up in between the cylinder skirts and sqeeuze it)
push the piston in just far enough to "lock" the top ring inside the bore
double check the locator pin on the second ring as the ring may have moved and repeat the process

this is the time to replace the base gasket

with the piston partially installed i turn the whole thing around and gently slide the cylinder over the studs lowering it down to a position where i can connect the wristpin to the connecting rod
i usually put a small 2X4 on iether side of the cylinder to let it rest on while i install the wrist pin and i ALWAYS place a rag underneath it in case my circlip decides to jump ship on me (would hate to see it disapear into the bottom end)

with the wristpin installed (dont forget the bearing) and both circlips in place i can now remove the 2X4 and lower the cylinder down onto the bottom end
i usually pour a bit more 2 stroke oil on top of the piston and tighten the nuts on the bottom studs, then i cycle the piston a few times with the kickstarter to ensure it all seems ok and im set to button her back up


i should have asked this before getting this far but which service manual do you have?
there is a misprint floating around which has the KIPS valves switched, the correct way is described here
http://kdxrider.net/forums/viewtopic.ph ... hilit=kips

oh, one more tip
if you read through that post you will get to a line that reads "now comes the tricky part"
i have found that that part is real easy of you lift the valve up slightly, allowing the shaft to travel underneath the gear it will mesh with once properly installed
once the two marking are lined up you just drop the subvalve in and your set to go

[bazzman]

i should have asked this before getting this far but which service manual do you have?
there is a misprint floating around which has the KIPS valves switched, the correct way is described here
viewtopic.php?f=77&t=9307&hilit=kips

diymirage,
isnt the above pertaining to a 95'+model kdx200?..this guy has a 90' so the kips is quite a bit different on his!...does anyone know if the older manuals(89-94)are correct pertaining to the kips valve assembly?..or are the 95+ manuals the only ones with incorrect information?

[stansama]

Thanks for the tips! I had read about the valves being confusing, but when you look at the assembly it's quite obvious how they work together. The tricky part was holding the left and right valves in the correct spot while sliding the rod through. What I did was insert the center valve to the notch, insert the right valve and held it so the gears were level with the cylinder surface to allow the rod to slide between the valve and the gears, then the same with the left valve, mating the dot on the top of the gears with the mark on the rod. Then the center valve slides in all the way, the right valve gets aligned with the mark on the third gear and presto! Not so bad.
I just finished putting the new piston in and got the cylinder on, everything seemed to go quite smoothly. I actually decided to put the piston on the rod first, and then slide the cylinder over while squeezing the rings, making sure they stayed in place. Turned the engine over a few times to make sure nothing was catching, everything seems to be silky smooth. I need to hit up the city tonight to get some fluids so I'm going to finish bolting everything together today and hopefully tomorrow I should be ready to start her up!

[royadams]

Make shure you break that piston in right
If you don't heat cycle it properly it could turn oval shaped on you.

[stansama]

Yes I plan on doing a few heat cycles in the garage and then taking it out easy after re-checking all the bolts.
Can anyone tell me how the kips valve should operate when installed on the bike? I expected it to open hard and snap shut, seeing as there should be spring tension on the shaft when it opens. It does move a lot harder then when the cylinder was off the bike, but it stays open if I pull the slide out, is this normal? I want to be sure it's working before I bolt the engine in completely. Does it need to be running to pull itself back to the closed position?
Took a few hours but I managed to get the old swingarm bearings out and the new ones in. Cutting a slit in the bearings helped, but they were still really stuck on there and I had to drive a flathead between the bearing and swingarm before they would release. Luckily the new ones fit right in without a hitch!

[Julien D]

Nossir, it should pull itself closed when you release the rod. Something is binding it up.

[stansama]

Damnit I had a feeling something was wrong. This will be the third time I've taken the right cover off, first time I missed the clutch sleeve somehow, second time the shaft had zero resistance so it had obviously come out of the advancer assembly. I'm not sure what's happening this time, it must have just come out of the lip or something and got caught on the wrong side. Oh well, here goes another attempt!

[stansama]

Well I figured out what it was, the small governor lever that goes into the advancer assembly, on the bottom of the shaft was bent inward, and not making enough contact to stay in the assembly. I tried bending it back out but it snapped, of course. So I need to wait for a new one, but in the meantime can I heat cycle the engine since I wouldn't be opening the kips anyway when I do this? And if I do should I get a new right engine gasket for when I open it up to replace the lever?

[Julien D]

Yeah it'll run without the powervalve and not damage anything. For the record, the usual cause of that damage is removing the LH thread nut from the top of the advancer rod without supporting the rod to prevent it from turning. When it turns to the left, it puts pressure directly against that pin and bends or breaks it. Glad you caught it before you ran the engine. That broken off little pin can cause a surprising amount of damage in a running engine. You will probably be able to re-use the gasket.

[stansama]

Thanks Julien. I do recall hearing about that, and I made sure to hold the shaft when I removed the nut but I never inspected that rod until reassembly. Not sure if it was bent before or if I did it, but oh well not a big deal. Only $7 to replace shipped to my door.
Can someone explain to me how the clutch works in the kdx? I'm confused as to how the lever that goes into the clutch case interacts with the pusher assembly. And shouldn't this pusher assembly slide into the clutch without problem and move freely? I recall it came out easily, but it doesn't want to go in without force now, and I can't spin it by hand. Tried in neutral and in gear, no difference. I'm not sure what could have changed, I removed the clutch as an assembly to get at the kickstart gears and put it back on the same way. It seems as if the clutch is off center a tiny bit, cause the rod will go into the bearing easily, and the rod will go into the clutch easily by itself, but with the bearing and housing in the clutch the rod is very tight. I'm not sure if this is a problem or not?
Thanks for all the help so far everyone, this site has been extremely useful while doing this project as a first timer!

[stansama]

Well I've been away at work for a week, finally have a chance today to get the bike back together. Here's hoping for a successful day! Still curious about the clutch and pushrod if anyone can shed light on this