Hey all,

I have been wanting a sweet vintage DT250 for quite some time and finally got one for song over the weekend.  It's rusty but generally complete.  Let the revival begin. So far I am waiting for a battery and just de-rusting some stuff.  Plan is to get it running before I tear anything much apart.  So far:

1. Piston and cylinder look ok - minor scuffs, but I think it's fine.  I plan on checking compression.
2. Chain is rusted but I took it off and it's soaking now.
3. Shifts in all the gears and has oil that looks decently fresh (will be changing anyway).  pre-mix looks and smells ok too.
4. Tires are old and some knobs look beat up, something for later.
5. Forks need work - they feel soft to me
6. Seat is soaked in water
7. Title is missing

So ya, pretty much a gem right?

I have the urge to start stripping but really want to just hear it run before I get too carried away.  

Couple of pics

Epic find. Although can’t see the photos. Enjoy the resurrection of a great bike

  

Just FYI, chains are case hardened and rust kills the strength FAST.  I would not ride it 10 feet with a chain that's been rusty as breaking one can cause a LOT of damage.  Don't ask me how I know.  

Chains can be bought pretty darn cheap, a new RK standard chain is only $32 here in the USA and it's better quality than what the bike came with.  That's probably even cheaper than the time and money to clean the rust off. 

(Even if it's not cheaper, it's definitely false economy IMHO to try to use a chain that's been rusty.  I snapped one in about 10 seconds, side plate let go and took out the cases.  )

Hey MarkT, that's good advice!  I'll buy one for sure.  I think it's a 520 with 104 links, but I'll measure now that it's off.

Good plan.  I usually just buy a longer chain and shorten it.  For some weird reason, often a 120 link will be cheaper than a 104 link for example

Here's a pic I found on the internet that is similar to the failure I had, except on mine the piece came out of the end of the plate like you'd expect. The chain in the picture doesn't look that bad and like it could be cleaned up?  Mine wasn't even that bad.  



I was going to college at the time and one of my professors (who was my faculty adviser) helped me analyze the failure in the lab.  We also randomly checked other parts of the chain and they were fine.  The section that broke lost the very thin layer of case hardening and the metal underneath was more brittle than the the other areas we tested, all from the rust in one little spot.  

Nice!  Love science (Mechanical Engineer myself).  New chain on order, battery in.  Firing it up this weekend wish me luck.  Once the photos can be posted I will share my progress.