New guy, just picked up an 89 kdx200.

julien_d

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Oct 28, 2008
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Hey all!

I've been doing a lot of reading here since I started shopping for a KDX a couple months ago. Great site!!

I just picked up a 1989 KDX200 that's in need of some attention. I was told when I bought it that the only thing it needed was the kickstart assy rebuilt. This turned out to be somewhat false, as a bead from a bad braze job inside the case just under the kickstarter gear was interfering with the gear mesh there preventing the kickstart from working.

Long story short, I got that taken care of temporarily, and fixed some other issues in there such as an incorrect clutch basket that had been installed and did not fit properly, and some foreign material in the case from the brazing that had been done as well as the incorrect clutch basket clearancing itself against a gear. The top end had been fitted with a new standard size wiseco piston and rings before I picked it up.

I got it started up yesterday, and did a few heat cycles and then a couple easy runs to seat the rings. When I was comfortable opening it up, it seems to lack power on the low end. It runs smooth and pulls well, but will not get the front wheel up even in 1st gear.

Anyone have some advice on where to start looking? I'm looking to clean the exhaust, repack the silencer, check KIPS operation (not quite sure on how to go about that one), check for air leaks, and then move on to jetting. does this sound about right ?


Let me know what ya'll think! I'm just happy to be here!! lol.


J.
 

sr5bidder

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Oct 27, 2008
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congrats on the green J.
make sure it is completly warmed up as mine does not give full power untill its nice and hot, then the first ten feet of every gear the front wheel is about 4-6 inches off the ground unless I 'm in the attack position, also check everything by hand spinning wheels brakes transmision out of gear anything that may be tight or causing drag.
There is a good wright up on the kips system google justkdx and go to the kdx tech tips.
the kips should be closed when at low rpm and open as rpms rises. while you had the clutch cover off did you inspect the governer that actuates the kips?

also check with the former owner and see if he had replaced the reeds lately they may be wore out
 

julien_d

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Oct 28, 2008
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The former owner acquired the bike from who knows where. He had a bike shop, and this one has been sitting for 2 years with the kickstarter problem.

I'm not very familiar with the kips. I checked the gears and rod for the governor and everything LOOKS ok to me. Nothing broken or seemingly out of place, and I can move the rod by hand with the lever disconnected. It's a bit sticky, but doesn't feel "grabby" or "grindy".

I have seen the kips write up on justkdx tips section. I'm going to take the carb out one evening this week to take note of the installed jets, and pull the intake boot off to check for cracks that may go all the way through. I'll check the reeds while I'm in there. I probably did not let it get warmed up, since it was leaking oil and water from the lack of gaskets. Some fool put it back together without a single gasket on the right side, just some kind of black silicone. blah. Lots of cleaning I'm sure to get the new gaskets to seal when they arrive.

Thanks for the info!! I'm really excited to have this. I have several bikes, but the only one I have running well right now is a 1973 Kawasaki F11 250. Fun old bike! I can't wait to get the KDX out on the trails!!

J.
 

sr5bidder

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Oct 27, 2008
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i've got some old ones too
I hope you got a deal on that 89. If you got a complete gasket set I would go ahead and check the prev. owners work ie. head, piston sleeve. wont hurt to take a peak and make certain the piston is in right and the cyclinder is in good shape. If one skimps on gaskets who knows what else. its so easy to pop that whole engine out and get it into some light and really look it over

As far as the carb I would take note of the jets sizes , clean the jet and carb and reassemble exactly as it was and do not change the float settings unless you have to (leaks out overflow)

Did you say it had the wrong basket installed??

And what was brazed on the inside of the engine??
 

julien_d

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Oct 28, 2008
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There was a spot just under the large gear on the kickstart shaft. It's the bigger gear, i guess called the spur? It looked as if somone had put the kickstart lever on without the inner clutch cover on and cranked down on it. The crack is directly below that gear. It was brazed from the inside, I assume so that they did not have to pull the motor to get to it.

I think I got a good deal. $400 and after a few hours of wrenching it runs. What do you think? I'll toss some pictures up tonight or tomorrow. It's really clean, all the plastics are decent, etc.


J.
 
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sr5bidder

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Oct 27, 2008
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I picked up my 98 4 weeks ago for 700 bucks it had a new cylinder and piston and the fmf torque pipe but it had a purple seat. I put a gripper seat cover new bars and foot peg springs on it and a new dunlap 756 rear tire and new rear frp chain guide. this winter I will do a new clutch as it wont let me roll it in gear engine off maybee warped plates but overall I really like it compared to the heavy enduro bikes I've had xt600-360lbs, xl350r-286lbs, xt350-248lbs and the lighter 1984 rm 125 198lbs but had no low end power and a unpredictable power band.. too sketchy!!

I have no need or desire to modify any of the engine I just want to add to the durability of it and tune the handling. and learn how to ride better.
 

julien_d

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Oct 28, 2008
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That's funny. I almost bought a 98 rm125. I do mostly easy trailriding though, so I wasn't really looking for an MX bike. That "sketchy" powerband is a bit too much for me. I've spent some time on my buddies yz250 and it's just plain scary. I can't see managing that thing on the tight trails we ride.

I've been watching for months for a KDX close to me. I live in a pretty remote area, and good deals on decent bikes are very hard to come by. I drove 2 hours to pick up this 89. My budget for this was zip, so the price on this one was right. I like working on them too, so it seemed like the right bike for me. So far I still feel like I got a good deal. Time will tell!

J.
 

julien_d

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Oct 28, 2008
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I got the top end off tonight, and the right side covers are off again as well. The piston is definitely brand spanking new wiseco. Looks pristine still after my break-in and 30 minutes of riding. The cylinder wall just has a minor spot or two that looks like a previous mild seize or something from a previous piston. Small aluminum deposits. I'm going to have a go at honing it very lightly, and then I'll do another break-in when I put it back together.

KIPS valves are very smooth and clean, no problems there that I can see. It looks to me like everything is in excellent condition, but was put back together poorly. Lack of gaskets on the entire right side, and top end gaskets that look as if they've been R&R'd several times. I'm really lucky that nobody actually ran it like that! Especially the wrong clutch basket and poor brazing job.

Aside from what I found in the first post, and in spite of even, everything looks in great condition, and really clean. I'm thinking I'll go ahead with the stock pipe mod while I have it apart. I have no problem cutting and gutting the pipe. I'll have the local machine shop weld it back for me though.

I didn't get the carb apart to check jetting tonight, and we're doing the top end on my buddies yz250 tomorrow so it will be later in the week before progress continues. I'd really like some advice on the the jetting. I'm at about 3000' where I live, and anywhere between 2000 and 4000 where we ride. Stock pipe (to be modded), and no airbox lid. I simply don't have one, lol. Riding style is tight technical trails, not much wide open running except the occasional speed blast up the road for kicks.

More to come!

J.
 

sr5bidder

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Oct 27, 2008
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are you sure the "deposits" are not where the plating has worn through??
I really don't think you should hone plating
if it is indeed aluminum stuck to the plating maybee a razor could get under it a peel it off carefully
 

julien_d

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Oct 28, 2008
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It definitely looks a bit "raised up" as compared to the rest of the wall, and not worn off. I'll try to do some research on honing the plating. If that's a no go I think it will be fine anyway. The cylinder looks to be in good shape, much better than I would have expected for something 20 years old.

good call. it seems you can use a deglazing hone on them, but it's best to just clean aluminum deposits out and deglaze with a scotchbrite pad. Sounds like the method to use. :).
 
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sr5bidder

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Oct 27, 2008
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you may want to take it to a machine shop and have it measured along with the piston
if there is a deposit on the cylinder wall and nothing appearanty wrong with the piston then how much clearance is there??

p.s. its nice to know where somebody is from, you can update your profile pretty easily
 

julien_d

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Oct 28, 2008
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Ah, sorry about the profile. I'll get that updated. I'm in lovely Boone, NC.

You can definately see where the small spot of aluminum on the cylinder wall was scuffing against the piston. I had only run it for just a few minutes total, apparantly not enough to score the piston up or anything. I imagine it could have gotten worse quickly once it got fully warmed up if I'd been slamming on it. I can run it by my buddies shop and check the clearances pretty easily though, I'll do that.

Oh yeah, I forgot to mention. The guy threw in an extra cylinder that has some pretty bad scoring inside. My plan was to roll with the cylinder and piston that was installed for next summer, while having the spare cylinder punched and sleeved. Next winter I would do another top end with the sleeved cylinder and a new standard piston.

J.
 

sr5bidder

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Oct 27, 2008
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yeah if you have it sleeved would you go with the 220
I really don't know if you can somewhere i read that the port timing is different so I guese the sleeves would be diferent.

I think r&b can do a 244 big bore for you but again its probably
better to stay stock and reliable
 

julien_d

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Oct 28, 2008
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sr5bidder said:
yeah if you have it sleeved would you go with the 220
I really don't know if you can somewhere i read that the port timing is different so I guese the sleeves would be diferent.

I think r&b can do a 244 big bore for you but again its probably
better to stay stock and reliable

Just stock was the plan. I don't really need to get much more power from it. All we do is easy trail running, mostly tight stuff. There's a couple spots where we can open them up, but not much. As the bike sits I don't think I'd have a hard time keeping up with my buddies yz250 while we're in the woods. When we get out in the open it'll be a different story, of course.
 

glad2ride

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Jul 4, 2005
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The 1989 - 1994 KDX200's can't use the power valve system if the bore size is increased. They are too close to the cylinder to still be used.

Muriatic acid will eat off the aluminum bit.
 

julien_d

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Oct 28, 2008
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I have some muriatic acid, that's the plan. I find cylinder sleeves for 89-94 KDX200's. Are you saying it can't be punched out and sleeved ???
 

sr5bidder

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Oct 27, 2008
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shure it ca be sleeved I think what julien was saying is that a big bore would not work due to the kips system..the rotor valves could not be installed/used
 

julien_d

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Oct 28, 2008
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Right. I found sleeves for about $80 from L.A. Sleeves. Seems like it will be a good investment. I can run the cylinder and piston I have until compression gets low, and then swap for a new wiseco and the sleeved cylinder.

I'm still waiting impatiently for my gasket set to arrive. That's pretty much all I lack at this point to get it cranked back up. It's supposed to be rainy and cold here this weekend, so it would be a good time to get some wrenching hours in. Next weekend perhaps could be spent riding :).

I have an old F11 that's at my buddies shop, we'll be splitting the case next week and putting new crank bearings in as well as a new top end. That's a fun old bike and I'm excited to get it back into the garage alongside the KDX.

J.
 

julien_d

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Oct 28, 2008
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Got my gasket set today and started putting stuff back together. I noticed the dowel pin is missing that goes in front of the main gear and secures the water pump drive gear. The set nut for that assy is also pretty stripped out. I went ahead and ordered those two parts before I finish sealing it up.

I had my guy at the shop look at the cylinder, head, and piston. All in working order. At least, my guy says I'll get by with it for a while. The piston has a decent scuff from rubbing on that aluminum deposit, but a quick wipe down with muriatic acid took care of the aluminum piled up on the nikisil inside the cylinder. The plating looks good, except a tiny bit of gouging around the exhaust bridges. We decided it's OK for now, but I'm going to have my extra cyinder sleeved as soon as funds allow, and on hand for a rebuild sometime next year.

I went ahead and cut / gutted the pipe. Man, getting that inner lining out was a @$%^. Jetting in the carb looks to be stock right now. 158 main, 48 pilot, and 1172 needle. I think those are the stock jets, correct? I have a buddy with a MIG welder, we'll get the pipe back together monday or tuesday evening, and hopefully my parts will arrive shortly after that. Should be ready for a second test run late this week! :cool:

Just throwin in an update! Hope ya'll are all well.

*edit*

Man, I just finished dissasembling the spark arrestor. What a mess! I don't think anything was going through there! I have the pieces in submersion cleaner now. Hopefully she can breath after all this! Generally I will need to richen it up a bit after opening up the exhaust, yes? What jets should I have on-hand?


J.
 
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sr5bidder

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Oct 27, 2008
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julien

I would just put the carb back together as is, I'm really not understanding what its is you did to your pipe.
I understand the silencer cleanup and repack.
I need to check mine out!
there are some really good deals on egay as far as used pipes for the 89-94 kdx.
FRP sells a torqe ring for $10

I'm glad to see that you are seeing things wrong and being patient and fixing it right.
Did you need a clutch side cover? or was it the case that needs replaced? (brazing)
 

julien_d

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Oct 28, 2008
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it's the right side engine case that is cracked. Just a small crack, and I think i can stop it leaking for now. Will pull the engine after I'm sure everything runs well and get it brazed correctly.

I'm going to place the carb back in as-is, since the jetting is close to what is recommended on the KDX tips.

Here's a link to the mod I did to the pipe. Heading over to a buddies tuesday to get it sewn back up with the MIG welder. Basically you are removing the inner pipe and insulation from the double walled pipe. There's about 3/8" of insulation in there, and a perforated metal pipe inside. It's all about noise reduction I suppose. Not as important to me as the performance, so it's gutted!

http://justkdx.dirtrider.net/pipe.html


progress continues. Currently waiting on those parts from bikebandit, and getting the pipe welded back up.
 

julien_d

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Oct 28, 2008
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The crank nut and pin shipped today from bike bandit, yayy! I also got the pipe welded back up tonight. We plugged the ends and pressure tested it. We had to go back and fix a leak or two, but it's all sealed up now. Not the prettiest thing in the world, but we'll see what kind of difference it makes. That thin metal is a bear to weld on.

J.
 

julien_d

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Oct 28, 2008
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Thanks! Hoping the parts from bb get here 2morrow. I have every single thing I can put back on at this point. I'll just need to install the pin, water pump gear, nut, and right side cover. Then It's 1-2-3 ride (hopefully!).

J.
 

sr5bidder

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Oct 27, 2008
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yea man I know the felling my 84 xl350r was a 8 month project.
but man does it feel good to jump that kick starter and bring it to life after 7yrs on ice
 
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