Need some input.. clutch or tranny issue.

[flounder]

Alright so heres the deal. First off let me say that Im not new to bikes and definitely not new to forums. I just wanted to get some input prior to starting to rip into the repair.
So anyway.. I have an 02 yz 250 2 stroke. While riding today, I stopped to clean my goggles and had the bike in neutral.. well I gave it a decent rev to help keep from fouling the plug and it felt like it slipped into gear. It pretty much stalled instantly. Well after I start it back up and take off, I notice that it wouldn’t let me downshift down to 1st.. pretty much sure I started out in second, grabbed a handful of clutch and tried to downshift and the tire locked up instantly with the clutch engaged, I upshift quickly and based on the way its running, it feels like Im in third. I try downshifting again and the same thing happens.. WTF. So I shut her down and evaluate. Bike is now off, I can squeeze the clutch and shift through the gears by rolling the bike but only in one of the gears can I actually roll the bike with the clutch engaged.. all the other gears even with the clutch engaged causes the tire to be locked up. For the one gear I can roll while squeezing the clutch, if I release the clutch, the tire will lock up as well so I know that Im not in neutral. Not sure what is going on now.. so I get back on start her up,, manage to find a gear that will let me at least ride it back to the truck to load it but if I downshift, it locks up.. Feels like I can only start out riding it in 3rd. Also, I cant seem to find neutral anymore.. Any suggestions would be greatly appreciated.. I have no idea as I wouldn’t think a clutch would act like whats its currently doing. Hell, I almost think its part clutch part tranny.

 

[Isobareng]

My first guess would be a bent or broken shift fork

 

[DieselTech]

Or a bent shift shaft (hope for that) maybe

 

[whenfoxforks-ruled]

Check your gear selector to drum orientation, and the drum ratchet pawls.

 

[flounder]

Thats for all the thoughts guys.. any advice on how hard this will be to crack open and attempt to fix..

Another friend of mine said that it also might be a messed up clutch basket and bad plates but Im not sure I agree based on the wierd shifting and the tire lockup. the other thing that bothers me is that I can shift through the gears when the bike is off but when I roll it, the tire locks up.

Im just deciding where I need to start and what I should tear apart first to examine.

 

[flounder]

Well tore the clutch out and the plates have definatley been hot and the fiber ones are shot as well. Only a few small notches in the clutch basket and not enough to cause what is happening. I took the clutch out to MJ USA here in Columbus and they said I should get a new one but based on what is happening, the clutch should be working but not to its full potential. So I went home put the clutch back in and took the entire bike out to them. He messed with it in the parking lot for a few min and said, I hate to break it to you but you have tranny issues. Said it would be around 500-600 to get in and fix it if they did the work. I only paid 1800 for the bike so that was definitely not an option so I went home and started wrenching. Currently the engine is sitting in my basement. With all covers off, drive gears off, kickstarter out piston and cylinder removed, etc. Basically all I need to do is pull the stator off and split the case of which I will be stopping by harbor freight tonight to get a puller to remove the stator. Tomorrow I will be splitting the case and seeing what I can find. So far I haven’t found anything out of the ordinary. No metal shavings, no ground down teeth, nothing. So Its going to be like Christmas tomorrow, I will either get something I can fix or else you guys will be able to buy parts from me as I part out the SOB. Wish me luck, I will keep all posted. Also, I have been taking pics the entire time of the teardown process so I will post those soon. I appreciate all the feedback from you guys. Guys I just got one of those touchy ones. One thing I have noticed so far is that the crank seems to have just a bit too much play in it but I will have it measured once I split it open tomorrow. Cylinder and piston look fine though so maybe its not an issue.

 

[Rotorranch]

Basically all I need to do is pull the stator off and split the case of which I will be stopping by harbor freight tonight to get a puller to remove the stator.

NO, NO, NO...do not use anything but a flywheel puller designed specifically for your bike!

About $15 or less from any mail order motorcycle supply, or even your local dealer. Anything else is quite likely to ruin the flywheel.

Rotor

 

[whenfoxforks-ruled]

And is very dangerous, get the removal tool, it is cheap works great, and fits damn near every jap bike!

 

[76GMC1500]

I had a transmission lock up on me, (it was quite an ordeal with a crummy dealership). The dealer assembled it wrong and it hit two gears at once. They replaced the gear that broke during the lock-up, but didn't bother to look at the others. 150 miles later, the other gear involved in the previous lock-up broke apart. A very cursory visual inspection revealed many cracks in the gear. What I'm saying is, check your gears after such an incident. You may even want to magnaflux them.

But, the actual cause of your problem is likely within the shift forks or shift drum. You'll have to split the cases.

 

[whenfoxforks-ruled]

Flounder, did you check all the parts behind the clutch, that control the shifting and shift drum?

 

[flounder]

Well I split the case tonight.. appears to be something with the shift forks or shifter paw. It is really hard for me to tell since this is the first motor I have split. I am going to take it to the dealership tomorrow to have them look at it and verify. Basically it appears that 2 gears are engaging at once. (Bent Shift fork).. Crank seems to be gone as well. (At least the rod is shot.).. I will hopefully know for sure tomorrow about the shift forks. I inspected them but I cant really tell if one is bent so I will have the dealer check it for me to make sure.

 

[flounder]

Well, I figured it out last night. Looks like I have one bent shift fork but even moreso, the 5th pinion gear is seized on the axle shaft. No idea how it happened. Im going to try and press it off this weekend to see if I can save the shaft. If not, I will have to get a new shaft, and 5th pinion gear, and shift fork. I thought about buying all new shift forks but the cost is started to get to the point where it is not worth it. That is due to the fact that it needs a new crank and clutch kit as well. So Im planning on ordering parts a few at a time and once the transmission is working, then order the crank and clutch kit. Im half tempted to just part the entire thing out on egay and start fresh but since I already have it apart, I may as well fix it. Im also debating on leaving the stock crank in it and just riding it until it goes and then just total out the bike. What would you guys do?

 

[RM85rider123]

by this point I would be so pissed off, I would give up on it. Same thing might be happening to my shift forks. good luck!

 

[flounder]

by this point I would be so pissed off, I would give up on it. Same thing might be happening to my shift forks. good luck!

Just dont ride with your feet putting any pressure on the shifter. It causes the shift forks to rub, get hot, and then get bent easily.