New guy w/ Clutch or Trans issue

sanstoetter · Post by **sanstoetter** » 03:21 pm Mar 03 2015

I just picked up a 93' KDX for a steal knowing that it had trans/clutch issues. Now that its in my possession I'm going to tear into it this weekend, but I wanted to test the waters to see if anyone's dealt with this issue before. That way I'll have parts ready to go, and maybe go for a ride this weekend.

Right now the bike starts up well in neutral if the clutch is pulled, but rolls as if in 2nd gear once the clutch is let out (but as if badly slipping clutch). If I shift out of neutral into any other gear, and the rear wheel locks up. When I let out the clutch the motor will also stall out if in any gear but neutral. I do know someones fiddled with the clutch cover recently as its sealed with red RTV.

Do you think this is an improperly installed clutch, or something more major possibly jamming the gears?

Thanks for any help!

...and yeah I need to organize/clean out my garage.

Post by **bufftester** » 04:00 pm Mar 03 2015

The KDX's are notorious for their dragging clutch in Neutral at idle, very common when the clutch pack is worn. And the red RTV is never a good thing to see. Get a new clutch cover gasket, and wouldn't hurt to get a clutch kit (springs and plates). Also check your clutch cable for wear, and if its near the end of its adjusters replace it. Even with a new clutch and fresh oil don't be surprised if the bike drags a little in Neutral with the clutch out, but it should be subtle. While you're in the clutch check the basket for notching (lots of threads here regarding that) and take care of it if present. An impact wrench will take the clutch hub nut off lickety split.

A quick search yielded these for the clutch dragging:
http://www.kdxrider.net/forums/viewtopi ... ch#p159646
http://www.kdxrider.net/forums/viewtopi ... ch#p159081
http://www.kdxrider.net/forums/viewtopi ... ch#p155835

clutch rebuild:
http://www.kdxrider.net/forums/viewtopi ... ch#p159344
http://www.kdxrider.net/forums/viewtopi ... ch#p157705
http://www.kdxrider.net/forums/viewtopi ... ch#p157150

and general clutch stuff:
http://www.kdxrider.net/forums/viewtopi ... ch#p157861
http://www.kdxrider.net/forums/viewtopi ... ch#p154971

sanstoetter · Post by **sanstoetter** » 04:22 pm Mar 03 2015

I'm not worried about the dragging so much in neutral, but right now it acts like the rear wheel is locked up no matter what Im doing with the clutch in all gears. It'll stall the motor if I let the clutch out in gear. If I try to slowly let out the clutch with the trans in 1st, the motor will drag until it cuts off, and won't even try to move the bike.

The drag is a bit much though... I rode up to 15ish mph in neutral up hill. I could rev the motor while cruising up the hill like a slipping clutch in gear though.

Post by **bufftester** » 08:23 pm Mar 03 2015

Ah, I misunderstood your OP. So the rear wheel turns in Neutral only, any other gear and it locks up. Have you had it on a stand and run it with the rear wheel off the ground? If the rear tire spins in neutral and locks up in any other gear on a stand you likely have tranny issues which would necessitate splitting the cases. The fact that it spins in neutral at least means the clutch side of things is probably working. Still wouldn't hurt to open the clutch side (you'll have to to split cases anyway) and see if there are bits of tranny floating around. Have you drained the oil and inspected it yet?

sanstoetter · Post by **sanstoetter** » 08:55 pm Mar 03 2015

Just drained the crankcase/trans., and the previous owner was definitely running auto trans. fluid which looked relatively fine. It was used, but not milky or metallic.

In Gear:
-Clutch In- Rear wheel is locked in place
-Clutch Out- Rear wheel is locked in place

In Neutral:
-Clutch In- Rear wheel spins relatively easily
-Clutch Out- Wheel feels in gear, and turns motor over when spinning.

squid · Post by **squid** » 08:34 am Mar 04 2015

Have you tried spinning the back tire and shifting it into gear while it was spinning?

sanstoetter · Post by **sanstoetter** » 11:27 am Mar 04 2015

Yeah, I tried shifting while rolling down a hill. As soon as it engaged the rear tire locked up while the clutch was pulled. As soon as I let out the clutch the motor bogged, and died.

doctord23 · Post by **doctord23** » 03:49 pm Mar 04 2015

It sounds like it is definitely in two gears at once.
Either a loose or bent shift fork, or possibly the shifter detent wheel is loose. I had that happen once.
The second one is easy to check if you pull off the inner clutch cover.
The first one will require splitting the cases.

squid · Post by **squid** » 03:54 pm Mar 04 2015

I had a dr350 that did that and it was missing the washer in between the backside of the clutch basket and the transmission shaft. When I pulled the clutch you couldn't turn the basket by hand. A new washer and tourqed it down and it worked perfect. That may be the problem but it's a wild guess

sanstoetter · Post by **sanstoetter** » 08:57 pm Mar 04 2015

I started taking the clutch side off today, and visually everything looks fine. I did see 2 metal slivers roughly 0.3mm x 2mm, but I did not see anything worn/broken. Are both of the clutch washers supposed to be the same? The washer in the basket seems like it could be slightly larger diameter. I plan to get a smaller magnet to see if I can find metal anywhere else.

Do any of you see anything glaringly out of place?

squid · Post by **squid** » 09:05 pm Mar 04 2015

If you spin the transmission shaft. Will it shift through the gears smoothly? You may have to remove the chain to spin by hand.

Post by **bufftester** » 10:20 pm Mar 04 2015

That side looks pretty good, which just gives more weight to a gearbox issue. Keep in mind that those slivers may have come from the gearbox as it shares oil with the clutch side. While you have it apart be sure to check your KIPS governor pawl, it is a high breakage piece (primarily due to it being LHT and shears when people torque on it trying to take the motor apart.) Hard to tell from the photos but looks like you may have a little basket notching (common) a flat file and some patience will take care of it and aid the smooth operation of the clutch when you put it all back together.

sanstoetter · Post by **sanstoetter** » 10:29 pm Mar 04 2015

The transmission shaft is not easy to spin, but I played with it in the different gears. The KIPS pawl seems to be intact... posted a photo below to confirm.

1st Gear- When spinning the rear wheel... the shaft rotates roughly 15 degrees.
Neutral- When spinning the rear wheel... the shaft rotates without any interference.
2nd Gear- When spinning the rear wheel... the shaft rotates roughly 80 degrees.
3rd Gear- When spinning the rear wheel... the shaft rotates roughly 100 degrees.
4th Gear- When spinning the rear wheel... the shaft rotates roughly 180 degrees.
...5th/6th followed the same trend.

Post by **bufftester** » 02:44 am Mar 05 2015

Looks like you're splitting the cases instead of riding this weekend

sanstoetter · Post by **sanstoetter** » 01:18 pm Mar 05 2015

I went ahead and ordered a flywheel puller along with a steering wheel puller last night in anticipation. Hopefully it'll come apart relatively easily, and it'll be something relatively cheap. I plan to clean up any carbon build up, replace seals, new gaskets, check piston/cylinder for marking, and check the rod bearing play. Anything else I should check out, or upgrade while its apart?

sanstoetter · Post by **sanstoetter** » 12:54 am Mar 07 2015

I also noticed some side-to-side play with the clutch shaft, about 1mm, should I replace those bearings? If so does anyone have the part number?

Jaguar · Post by **Jaguar** » 01:25 am Mar 07 2015

I think that sideways play is normal. Just check for play perpendicular to the shaft.

sanstoetter · Post by **sanstoetter** » 09:29 pm Mar 08 2015

Well I think I found the culprit.

Looks like the right gear (3rd/4th Input) right cannot mesh with the left gear (5th Input) correctly. To me it looks like 5th gear should be able to rotate one spline, and work correctly... or is 5th supposed rotate?

I've ordered an FSM, but since I do not have it yet, and if I need to order something I'd like to get on the way ASAP. I just can't get my head around how a gear would be on the wrong spline, and have ever moved under it's own power. Also it looks like I should probably replace the piston/rings while it's out. Any preference on Wiseco, Pro-X, or OEM?

Jaguar, Just realized you've been answering my questions in both forums. I seriously appreciate the help so far.

Jaguar · Post by **Jaguar** » 10:42 pm Mar 08 2015

Is it possible the previous owner reassembled it incorrectly and instead of digging back into it just decided to sell it?

sanstoetter · Post by **sanstoetter** » 02:35 pm Mar 09 2015

From what I can tell on an exploded view of the shaft it looks like 5th should rotate freely. So I ordered an input shaft with gears, and a Wiseco replacement 66mm piston since the stocker looks pretty well used. I'm going to try the air pressure method of popping dents from the pipe, and maybe porting the 34mm carb. a tad while I'm waiting. Any suggestions on other mods while apart? All in all I hope the motor comes together as easy as it came apart.

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