Seized top end 88 KDX

[dave04kdx]

I need some advice and this is the best place to ask.
Here is the scoop. My brother let someone ride his 88 KDX 200.
(My old bike) The guy seized the top end, tight. I got it to kick over yesterday but its thrashed, little compression, nasty scraping noise.

My question is, have anyone of you had a top end seize that tight and have the cylinder be ok? I rebuilt the top end of the bike about 1 ½ years ago and the cylinder was in excellent condition. I realize its most likely history.

If a replate is required where is the best place to have it done?
Where is the best place to get the piston, small end bearing and gaskets?

We are also replacing the clutch while it is down. Any recommendations on what clutch to use and where to buy it?

Feel free to chime in Jason! You are the king of the "C's"

[canyncarvr]

Was there rider error involved, along the line of a lean roll seizure mayhaps?

Maybe he dumped in some of his old truck fuel?

I've stuck more than a couple 2-strokes..what you describe sounds bad from the standpoint of cylinder health.

I'm using clutch parts from Vesrah. ..don't like 'em much. They're noisy..barkin' squeakin' and howling a good bit.

I would've said 'Ron Ayers' as far as 'where'...but the fact that you asked the question made me wonder...I just checked...the earliest model they list on their website is the '92 E4...so, maybe not.

Yeah...Jason knows..........

[KDXGarage]

Well that stinks!! I am sorry to hear about that. Do you have any further details on how it happened? I would hate for it to happen again if it were an air leak or something like that.

My best suggestion is to stop worrying and start knowing. Take it apart and see just how bad it is. Be sure to lubricate the cylinder walls/piston-cylinder junction well before trying to remove the cylinder.

Don't forget that the crankshaft bearings may have suffered as well. Be sure to check it all out.

I would suggest Rocky Mountain MC as it looks like $130 shipped for a Wiseco piston kit, Wiseco small end bearing and Cometic gasket kit.

I have never had a cylinder plated, but I would lean toward Langcourt, http://www.langcourt.com. They don't list a specific price for all kinds of cylinders, so you just have to e-mail them and ask. I have read that it is usually around $200 at most places. Of course, that is just me passing on something I read somewhere, so e-mail them for the direct scoop.

Kawasaki went from aluminum plates to steel plates or steel to aluminum in 1988, so get OEM '88 plates instead of '86 or '87 plates if you get a chance. Someone had some OEM plates for some year of KDX on eBay a few days ago. You may want to check on that. Otherwise, I guess it is just buy something cheap off eBay, buy OEM from ronayers or try some aftermarket brand. I have never replaced my plates, so I don't have any first hand knowledge to share on that.

canyncarvr, on the bikes that they don't list on the ronayers fiche, you have to go to buykawasaki.com and then copy and paste the part numbers into their search box. Sometimes that is wuicker for me than resizing the parts diagram window on ronayers, clicking on the part number, going back twice, etc.

[canyncarvr]

If you do get it replated be sure to send your piston with the cylinder.

No decent outfit will plate your cylinder without the pistion that is going to be used at hand.

If 'they' don't care if they have the piston or not to replate the cylinder...don't send your cylinder to 'them'.

I've heard good things about Langcourt. One of them is they specifically state they will not replate without the piston. Well...used to. Didn't check just now...

I'd tell whoever did it what I wanted for a piston/cylinder spec, too. If you use a Wiseco...don't use the spec in the service manual. Can't direct you to it offhand, but I've read clearance specs for Wiseco pistons on their website before. I'm sure it's available on the web from a reliable source. Do be careful about it, though. I've seen recs for .02-.08" depending on useage and application.

Wiseco didn't get the name 'Seizeco' for no reason.


**Most of the above for use by the casual reader. Dave's a hotrodder...he knows this stuff already

[KDXGarage]

When I was looking at their site earlier, it said something about sending in the new piston with the cylinder, so I guess you should shop at Rocky Mountain before sending in the cylinder. AND PISTON

[dave04kdx]

Thanks for the tips CC and Jason! I appreciate the input.

I just got done looking at RB Designs website and it looks like he sleeves and does not plate. I wasn't happy with the L.A Sleeve 240 Big Bore Kit, on my 86 KDX, the cast sleeve wore out way too quick.

I'm not sure how the seizure happened. My brother traded him bikes. We looked back and didn't see the 88. I went back and all he said was, "it stopped". No more information than that. Not very mechanically inclined I guess. He also managed to break the shift return spring during the ride.

I mixed the gas, same as in my bike. No problem with that. The guy was riding a well abused YZ 426, maybe a bike thrasher guy.

I'll check intake and air boot for cracks and such. I tend toward rider error. My bother has only ridden the 88 six or seven times since I sold it to him.

I'll get it apart this week and post results and pictures.

Thanks again guys

[KDXGarage]

Well, that stinks.

Let me know when you get it apart and checked out.

I would go for the plated cylinder instead of sleeved, too.

Thanks!

[quailchaser]

Dave,

That sucks. The best advice has already been given. Pull it down and verify the damage.

Monkeybuttparts has good prices on either a Pro X or Wiseco, top end bearing, and cometic gasket kit.

As far as the cylinder goes...if you need to replate it, you'll have to send the piston with the cylinder. They set the tolerances based off the piston. Personally, both the Pro X and Wiseco are good. The problem with the Wiseco is that if you don't let the engine warm up before you flog it.....Cold 'Seizeco' can happen! Once warmed up...flog away.

EBC Dirt Racer Series clutches are mostly what I've used in a variety of bikes. They seem to work well for MX and Offroad abuse. Barnett makes a great clutch kit as well, but it's a tad more expensive. Moose also makes a kit that works well. I think it's around the same cost as the EBC.


Good luck with the project. Hope you get it up and running quickly.

[dave04kdx]

I got the top end apart on the 88. Pictures of the piston and cylinder are in my gallery. The piston seized on the exhaust side. The skirt is cracked and the cylinder is gouged pretty bad. I am wondering if maybe this was a piston failure or maybe an overheatng issue? It was over 95 degrees when we were headed back that day.

[Green Hornet]

Well guys, a lesson to be learned. Before you let someone else get on your ride, look at his. If it's a piece of crap, get away from him. A lesson I learned the hard way. So BEWARE
Unfortunately the only way to find out is taking it apart. Good Luck

[KDXGarage]

Looks bad! Be sure to check the main bearings and for chunk damage in the interior of the crankcases.

[Indawoods]

Looks like a lean seize.... Air leak or straight gas?

Was the pipe seated well?

[dave04kdx]

Jason

I am planning on cleaning out the bottom end very well before it goes back together. I have read about guys pouring kerosene in the bottom end and then turning the bike upside down and dumping it out. What do you think? Any better suggestions? Are you going to be blasted my Katrina tomorrow Jason?

Inda: Good point on the pipe. When I took the pipe off the copper washer was all but gone, the springs has also lost some of the tension. The o rings were not sealing very well. We are getting new o rings, springs for the pipe and installing the pipe with a good coat of red rtv silicone.
I mixed the gas, 40:1 with amsoil dominator. Same stuff went in my bike that day.

[KDXGarage]

Oh I didn't mean flush it of shrapnel, I meant to check to see if it got danmaged from flying shrapnel. Any reason not to use straight gas to flush it with?

I am about 375 miles from the coast, so all we have had so far is the heat sucked away and a halfway decent weekend with cooler than normal temperatures.

[dave04kdx]

Jason:

I got a flash light and an inspection mirror and from what I can see with the bottom end assembled everything looks ok. I was thinking the kerosene would leave a bit of oil residue on the bearings.

We are also buying a new carb holder (intake). It isn't cracked but it crazed quite a bit. Good thought Inda.

[KDXGarage]

That sounds good. I would suggest that you break out the feeler guages and check the big end bearing play, too while you are at it.

When I started to rebuild my '87 back in '02, I had to buy a new carb boot. Mine had a lot of little cracks in it.