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Old 11-05-2013, 10:28 PM   #1
c0rn_d0g
 
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72 DT250 kind-of restore.

What seems like years ago was actually March or April. Gravel Guy was selling his DT250 and I got to it first.

I'm a fan of projects and old 2-strokes so this one was perfect. It was mostly complete, partially disassembled, and potentially only needed a clutch push rod.

Over the past few months I've worked on different parts of the bike here and there. I've grown to like the aged metal. I have no plans of painting it and making it pretty. What does matter to me is functionality.

THe first time I laid eyes on it over the internet, here's how it looked:


And the first night it came home-


Parts wise it's almost all there which is a huge benefit. I powerwashed the frame, cleaned up the years of grease, dirt, and oil. And then the engine came out of the frame to find out what was wrong.


I also did some carb work. I tried out the pine sol method for the first time. Worked amazingly well.




24 hour, unagitated, 100% pinesol soak. I would go on to put the carb in chem-dip to get off the powder coating. I'd leave the carb in there too long and ruin it. That stuff ate the aluminum almost to the point of unrecognition.

Engine plan was- put in good push rod from ebay. Replace main seals. Run.


As i got further in, i realized something else was going on. When i'd move the engine, I'd hear rattling. I could shift in to different gears, but non of them engaged the output shaft....hmm. Decided a splitting of the cases was in order. So i'd wait for time and money to buy the proper tools. In the mean time, i rebuilt the front forks and rear swing arm.





these "collars" were hard to find. but better than the old ones.



New tires, rebuilt forks, steering head, rear swing arm. Put in brand new brake shoes. ordered brake cables that I needed.



And by that time, it was case-splitting time. For perspective, I bought this in April I think. Suspension was rebuilt and done by June. Cases were split in July or so.



You can barley see the problem sitting next to the oil drainplug. It's a gear tooth. I'd suspected as much. And i ordered a replacement trans on ebay before opening the engine up.



Here's the problem-


So in more pieces than ever, i put everything in boxes and went hiking in california for a month to do the John Muir Trail. I got back, moved in to an apartment with an actual garage instead of a porch (which had been my workshop prior til now) And i've been working.

I decided that i want the engine to be the only thing that looks "new." So I decided to powder coat it.



Engine got all new bearings. The new used trans was taken down to component level and checked and then rebuilt.



Today the cases were bonded together, sealing the new transmission inside. I had a scare with the shift drum (i could only get first and second after pressing on the cases and tightening them up) but it was a simple linkage fix.



Right now i've got a bottom end sitting in the garage waiting for an oil pump.

I'm waiting on some small things like rings, an oil pump (ruined the old one in the b12 chem tool, as well) and a couple of gaskets. Other than that, it's ready to go back together and sit in the frame for the first time in almost 9 months. It's like having a baby! kind of. maybe. Never had one...

I'll keep this thread updated as I go along. Just wanted to share.
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Old 11-05-2013, 10:45 PM   #2
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Re: 72 DT250 kind-of restore.

Loved those bikes...
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Old 11-05-2013, 10:48 PM   #3
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Re: 72 DT250 kind-of restore.

A lot of confidence, buying tires before getting the engine running. I raced a 250 Yamaha back in 1971. I'll be watching and waiting for updates.
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Old 11-05-2013, 10:58 PM   #4
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Re: 72 DT250 kind-of restore.

A rolling chassis does wonders for the ambition.
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Old 11-06-2013, 05:03 AM   #5
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Re: 72 DT250 kind-of restore.

Fantastic!
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Old 11-06-2013, 08:12 AM   #6
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Re: 72 DT250 kind-of restore.

Awesome......keep the pics coming.
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Old 11-06-2013, 08:22 AM   #7
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Re: 72 DT250 kind-of restore.

Great rebuild. Probably ought to be filed under Vintage and projects but I found it!

How did the B12 ruin the oil pump?

I like Pine Sol but the jets take stronger or one of those wires that fit through the jet.

This is already an amazing rebuild - it survived a move!
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Old 11-06-2013, 10:26 PM   #8
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Re: 72 DT250 kind-of restore.

Sorry for posting in not the best spot

Here's a few pics from today.

Still waiting on an oil pump, piston rings, and gaskets.



Pleased with how it looks. It's not a show engine. but that was never the intent. It's been a lot of fun. Can't wait to see it in the frame soon.

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Old 01-15-2014, 11:12 PM   #9
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Re: 72 DT250 kind-of restore.

Here's where I'm at as of today after putting in the wrong trans, having to split the cases, order a new used trans, put everything back together and work out electrical and fuel bugs.

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Old 01-16-2014, 04:29 AM   #10
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Re: 72 DT250 kind-of restore.

I am SO happy that you ended up with this bike. It would still be sitting under my carport, unattended!
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Old 01-16-2014, 09:14 AM   #11
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Re: 72 DT250 kind-of restore.

boy that brings back memories that was my very first bike back in 1976
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Old 01-16-2014, 10:03 AM   #12
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Re: 72 DT250 kind-of restore.

Mojo, I was 5yrs old in 76. Just sayin. Lol


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Old 01-16-2014, 10:24 PM   #13
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Re: 72 DT250 kind-of restore.

*L* whats your point? sucks getting old
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Old 01-17-2014, 10:17 AM   #14
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Re: 72 DT250 kind-of restore.

Quote:
Originally Posted by mojo View Post
*L* whats your point? sucks getting old
Certainly no offense, I turn 43 in March and feel like I have the body of a 50 yr old.
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Old 01-17-2014, 09:16 PM   #15
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Re: 72 DT250 kind-of restore.

non taken, its not the miles you travel but the rough roads you follow
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Old 02-07-2014, 05:30 PM   #16
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Re: 72 DT250 kind-of restore.

I bought one from Wiede Cycle Sales in San Marcos Texas in 1976. I was 20 at the time and kept it in my bedroom. If I only knew then.... Gotta keep moving on. Enjoyed the pics.
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Old 02-07-2014, 08:29 PM   #17
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Re: 72 DT250 kind-of restore.

Awesome!!!! It is a labor of love. Look forward to seeing it at one of the rides.

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Old 02-16-2014, 10:55 PM   #18
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Re: 72 DT250 kind-of restore.

That sounds too cool. I like the color. Can't wait to see it finished.
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Old 02-21-2014, 12:12 AM   #19
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Re: 72 DT250 kind-of restore.

Not a ton to report. Lately I've been working on small things.

I ordered a new set of points and a condenser before it fired up. Figured it was a safe investment.

After the first breaths of life, i ordered a carb kit. I felt like I did a good job cleaning the carb and getting everything in good shape, but didn't want to chase that ghost...

I'd tried cleaning the tank out with evapo-rust and shaking some nuts and bolts around in there. Didn't work to well. After the initial test firing, the petcock bowl was packed solid with little rust bits.

So for a week, I put the tank through an electrolysis program. It exceeded my expectations. The process doesn't make the metal shiny and new, but it does physically remove the rust. So far so good. No rust flakes coming through.


Much better. Flash rust after rinsing. Knocked all this out with Phosphoric Acid.


As of today it starts on the first kick, idles, drives.

Things i'm working on-

Clutch. the nylon worm gear that pushes the clutch push rod when you pull the lever is pretty bad. After months of trying to get this clutch issue worked out (I could never generate enough force to make the clutch do anything) I've made progress. It takes my superhuman strength to pull, but i can get some clutch action after drilling a new mounting point for the cable attachment.

In the future when I have money, there's a mod to adapt an XS650 mechanism to the DT clutch cover. Require a bit of machining.

Seat. Pan needs to be reinforced. Instead of welding, i'm going to give composites a try. I've heard good results from reinforcing with fiberglass. I've made a replacement seat foam but it's not the greatest. I'll live with it until I feel like spending the $80 for replacement foam.
I've also sewn myself a cover for the new seat.

Rear shocks. They are trash. And not rebuild-able. Going to probably give these Chinese ones a shot. gotta be better than 40 year old technology even if they are Chinese. Shocks

Wiring Slowly getting the lighting circuit figured out and spliced all back together. The harness was chopped up when I got it but luckily it is 98% complete. I ended up breaking the left hand control switch trying to drill out a broken screw, so I need one of those. Planning on doing a 12volt system instead of the 6. My thought is if I use the charging circuit to directly power the lighting through a 12v regulator, I can power an entire LED lighting system. That's in the future, though.

Sea trials I need to see how easy this thing is to break. Seems to run strong around the apartment parking lot and respond well. Engine makes a little mechanical noise. I think it's the Crank/rod. When i was working on the clutch today, I took the cover off and inspected everything in there. Looked good.


Long long term-

Rod and crank rebuild. This was the only part of the engine I didn't touch because i couldn't source the replacement parts. If and when i find the bearings, spacers, and pins, I'll take an opportune time and pop the engine out, bust it open, inspect how everything is looking and get the crank rebuilt and slap a new piston on it.

Paint. Maybe. I kind of like the ugly look. If I do paint, I will probably just paint the frame.

TW200 Fork conversion Yamaha Big Wheel forks bolt right up. That sounds fun. Can also utilize a front disc brake this way.

Hydraulic Clutch I plan on trying to retrofit a hydraulic unit on the bike, but that's contingent on how the XS650 mechanism works. If it pulls smooth and easily, i'll save this for a day when i'm super bored and rich. Parts don't look to be expensive, though.

New rims, spokes, bars, small stuff.
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Old 02-26-2014, 11:22 AM   #20
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Re: 72 DT250 kind-of restore.

The clutch actuation should be easy to work. Something must be wrong internally or with the cable situation. No need for a hydraulic on that scooter if things are assembled/working properly.
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