Where we stand...
The last post came from a different home/workshop. Since then i've been a bit transient.
The bike is in storage in San Antonio though, and i'm able to work on it from time to time.
After getting the engine all bolted together I put it in the frame.
I tried bolting a YZ426 to the frame. I tried putting YZ80 forks in the original triples. Finally i settled on doing what I originally wanted to do- Bolt a TW200 front end on.
A guy on ebay was selling a late model front end with disc brake....forks, triple trees, wheel, tire, caliper, everything i needed. It was too perfect of a deal. So a reasonable (as in not egregious) sum of money later, and i get 3 huge boxes at my door.
The bolt up is simple at the TW front end uses the archaic ball bearing style steering head bearings. I was able to get a tapered roller bearing in the upper race and use the standard ball bearings on the lower due to the DT1 frame having an uncommon dimension. SO there it sits. Flat black frame, TW200 front end, shiny blue motor ready to roar.
What I really needed to make it run- An exhaust pipe and a gas tank.
I found a DT175 tank, seat, and pipe on craigslist from an estate sale. The tank was full of old awful smelling gas, but nothing that couldn't be sloshed out. The seat doesn't fit the DT250 frame, and the exhaust pipe was just a bonus. It was never going to work .
I did, however, find a mystery pipe on eBay. It looked like it'd fit an early DT250 and the seller said it was off a DT1. The bend as it exits the head was completely rusted through though. Holes everywhere. For $80 bucks i figured it was worth a shot though since the other chambers i've seen are regularly 200+
And so accordingly, i needed to buy a welder. And if you're going to weld, you might as well TIG weld. My efforts were poor and ugly, but they hold the pipe together.
After taking some measurements, i felt confident that i could by a section of exhaust tubing and just slap it on the pipe.
A 2" diameter U bend with a 3" radius would be a perfect fit for the original. I found one on summitracing.com from Patriot and proceeded to cut and weld over the course of some weeks when i'd visit San Antonio on weekends.
Over Christmas, i decided it was time to make it run. So the pipe was welded together in final form, the gas tank was cleaned, petcock rebuilt, and 30:1 premix put in it. Then came time to fire.
4 or 5 kicks later and the engine roared to life and sounds amazing. Sounds and feels very smooth.
The premix was a crutch since the bike has an autolube system. Consequently, though, the pump wasn't working. (I later determined this to be a leaking seal under the primer wheel, at least i hope thats the problem)
But i did ride it around after putting the old chain on. A couple of immediate realizations
- That pipe is LOUD. especially when the throttle is opened up.
- This engine pulls much harder than the DT2
- Throttle response is instantaneous
- that front disc has awesome stopping power.
It still needs a lot. Need a proper tank. Need to make a mold of the seat pan and get a seat made. Need to fix that oil pump (seal is in the mail) Need to tighten up the steering head bearings. Need an air filter. Need to fix a broken bolt in the footpeg mount. Need rear shoes. Need a new chain.
It needs a lot...but it'll out run the DT2 as is!