hi all,
just got done replacing front tire and fork seals on a 1975 dt 250 i lucked onto last fall.
i just pulled the rear tire to replace it and brake pads and i see one rear shock has been leaking. i don't see anything about rebuilding it in the service manual. does the procedure become obvious when you have the shock removed? are there any other printed instructions out there?
thanks in advance.
bob noffs

Yamaha made a replacement insert for hem, but they are quite rare. The seals are an odd size and seem to be unavailable.

I've seen where someone machined slightly to use a common seal, and it's posted here somewhere.

I just got a copy of a vintage article detailing the rebuild, just haven't gotten it scanned yet for the site.

that's great news.seems a shame to have to toss such such a substantial piece of equipment.much better feeling to rebuild. i look forward to the info.
thanks!
bob noffs

We Deliver! Even though we had to purchase a full year's worth of vintage Modern Cycle Magazines to find this one article, that is what your donation dollars do for the community! We spend them to improve our offerings!





Click Here to go to the download

That article is money well spent. Lots of great information in there and I learned that those old KONI shocks are more adjustable than I thought. Now to find a rebuild kits!!

Robert Hagg is the go to guy for Koni's. This email address is being protected from spambots. You need JavaScript enabled to view it., he was a pro racer way back and still does vintage racing.

The tech library 73 MX manual has rebuild info , its way in the back under bulletins, #317. I have seen rebuild kits on ebay, but there may be folks here that can rebuild them. I didnt have orig shocks for my MX250 so I bought Progressive, I think series 12.


yamaha-enduros.com/index.php/workshop/se...ctory-service-manual

thanks for the great article . after reading it i really don't feel like attempting the rebuild as no specs are called out for parts. i have been in contact with one person that rebuilds shocks for the 1975 dt 250. i may go this route. sounds like he has old spare parts too if your shock was damaged.
bob noffs

This may be bringing a tread back from the dead. But is there no one on this forum that rebuilds these old shocks? I feel with guys and girls with so much talent and skill that we would have at least one person...

I have rebuilt my own shocks for years... late 70's monoshocks most recently. I'm sure I'm not the only one.

Scootern29 is a real expert and has supplied rebuilt Curnutts for many of us here in "like new" condition. And if you have Curnutts already he rebuilds them.

The problem with the Yamaha twin shocks (Thermalflow) has been parts. Someone on this forum found some new seals that sound like they might work so if you ask Scott (Scootern) he might consider branching out to rebuilding Yamaha shocks?