Hello,

First post for me. New to the forum. I recently picked up a '75 DT250 that hasn't run for 30 years. It was garaged for 28 years and sat outside under a tarp (tattered when I found it) for 2 years. The bike is still in pretty good condition and I've been working through it to get it running. Still haven't started it yet as I can't find a spark and the transmission seems to be stuck in neutral.

I think I can figure out the electrical issue (new points and condenser on the way) but the transmission may be beyond my capabilities. I did a search on the forum and found one MX250 with the same issue although I didn't see that the problem was resolved in the thread. It was suggested that getting the bike running might warm it up and free the suspected stuck drum without the need to split the case.

What I've tried so far:
1. Try to shift in every possible combination of pushing, kicking, bouncing, clutching, etc,
2. Drain what little oil was left in the transmission and run some kerosene though it to soften any sticky build-up.
3. Refill with oil and try step 1 again.
4. Pulled the clutch off and looking at the mysterious parts inside.
5. Everything in the clutch area looks pretty good. The clutch plates need some cleaning and were a bit stuck but I haven't seen any rust so far.
6. Shifter moves up and down just fine and moves the shift lever up and down but never clicks into a gear.

If I understand what should be happening and isn't, it looks like the shift cam or drum is stuck. I haven't seen anything that indicates this bike was ever abused and I was told it ran normally when he stopped riding it.

Is it possible to get things moving by tapping or moving the shift cam/drum from the clutch side without breaking the case open? There was the suggestion that the MX250 mentioned before might free up just by running with some hot oil splashing around but it wasn't resolved in the thread.

Any help would be greatly appreciated. Thanks in advance.

Mike

Mike,
First, welcome to the site! It appears to be slow for responses so I am gonna throw out an idea. There’s a bolt that holds in a spring and cam stopper. See screen shot below. Parts 9-12. The head of the bolt should be easily visible but I am not sure where it is in your model. Remove the bolt, spring, and cam stop and spray some lubricant in there and reassemble. I assume your chain is on. Sit on the bike and roll it back and forth putting upward then downward pressure on shift lever. Hopefully it’s as easy as this cam stop having it stuck in neutral.

Yep, everything 'Midlife Motor' above says--save me writing lol. Only other thing is if someone's had the clutch cover off 'before you' & the lever shaft moved through then got pushed back in on a different tooth--think its 20 in your pic but bit hard to see the number. Even so i think you'd still get a part movement & one gear at least. With clutch off can yo grab the drum firmly but carefully & turn it 'at all'. Plunder & spring problems are unlikely unless rusted solid or someone';s spaced it up solid. Gonna be an interesting outcome but hope you don't need to 'go right in'.

Thank you both for the replies! If I've done it correctly, there should be a photo attached to this response. I believe I've removed the parts in question and it appears the cam stopper is stuck in the bore of the bolt. I'm hopeful that a bit of PB and some gingerly coaxing will free the parts from each other and this will solve the problem. I will definitely follow up one way or another once I get a chance later tonight to fool with it a bit.

Again, thanks so much, I'm feeling pretty positive right now!

Good job. Throw that whole assembly in a pot of boiling water if the PB blaster doesn’t work. I usually do this when wife goes to store or to see her Mother.

Good call. If you got caught you might be facing wife going to LIVE with her mother!

Don't forget to check that the spring is a) there and b) in good condition and functioning properly.

SUCCESS!!!! Thanks for the help!

Hit it with some PB, compressed air, then held the bolt head in the vise while I grabbed the stopper with a cloth and some plyers. Came apart after a bit of light twisting. Cleaned it up, stuck it back in, sewed the clutch back up and it snicked right into gear! What a relief and an easy fix. Now the waiting game for the various parts I need to get it fully alive and moving.

Thanks again everyone!
Mike

Great job Mike. Looking forward to more posts from you as your project progresses. By the way you are following a good path for getting lots of help on this forum. You posted the issue with bike and all the attempts you made to fix it. You gave the specific year and model of the bike. You posted pictures of your progress and final result. That’s how you get help on this forum!

Thanks! Here are some random pics from when I rescued it from a client's driveway and some of the progress so far. I suspect I'll be back here asking electrical questions soon!