Yamaha DT1F

There is a chart at offroad dot com forward slash dirtbike forward slash machines forward slash classicyamaha (you can't do web addresses here) for vintage Yamahas. According to the chart, your bike is a 1971 DT1MX. It is a 250. Cool bike. Pretty simple rebuild. I have a 1969 DT1B. It should be pretty similar.

The parts from 1968 to 1971 DT1s should be compatible. After 1972 you get into DT2s and DT3s. After 1974 they became DT250s. Some parts from the DT2s and DT3s are compatible. The DT250s are not usually.

Get a service manual. Have fun.

You're right, Kevin. When I glanced at the chart I thought it said that the DT1MX was up to 90000, not started at...

Still a very cool bike. My DT1 is a lot of fun. Another good web site for your rebuild, if it needs a rebuild, is Yamaha-motor dot com. It's the factory site. If you go to the parts section it has parts fiches on every model of Yamaha motorcycle ever made (at least all the ones I've heard of) including part numbers. That way you can tell for sure what parts cross between the models. It was invaluable to me when I rebuilt my DT1B. Check it out.

Patrick

Yamaha DT1

This thread is so old now and having just joined the site because of my interest in finding a suitable restore project I thought I would offer some information. The Frame and Engine number are in fact for a 1968 DT1F which was the first and original DT1. I worked for Ken George Yamaha in Western Australia from 1969 to 1974 at the time of the release and rise to popularity of these Yamahas. The 650 twin was the same , the first model being designated XS1F (drum brake, no electric start). Back to the DT's the DT1A was next followed by the DT1B and then reed valve DT2 and then DT3 before going to monoshock DT250A, B. C, D, E, and finally F. I know little about the models that followed this except that they are probably the liquid cooled engines although the 4stroke XT 250 was released and the 2stroke unfortunately virtually disappeared. The DT1F was available only in gold with black pinstripes or white with same pinstripe. All engine and frame numbers were 5 digit as apposed to the DT1A 6 digit. DTMX was not a terminology given to any trail bike with lighting etc but only given to competition models. We sold many of the DT1 CT1 and AT1 and AT1FE (125 electric start 12v) (some modified before the advent of purpose built bikes) to farmers who started using m/c's for sheep mustering in place of horse back. As an aside Western Australia also had a RD250G and back from the 400 to the 350 for the RD350G and these 2 models are never mentioned anywhere on the web that I can find. The tank shape reverted from the angular E, F models to a softer shape very similar to the first LC shape. It will not be widely known that WA was a huge market for Yamaha and the other Japanese m/c manufacturers.

Just some useless trivia I thought may be helpful to someone somewhere.

John

Even a 1972 DT2-MX is stamped DT1-F on the steering head. I would really need to see some pictures...A DT2-MX is a real cool bike. Love to have one.

Eric<><

Dt1f

All Yamaha DT 250cc twin shocks had the same frame No prefix i.e. DT1F As I pointed out the difference between the twin shock first model was that both the engine and frame number digits were only 5 in n umber unlike all subsequent models which had 6 digits. The question at the start of this forum asked what model he had with his engine. The number he quoted had only 5 digits. B.T.W. Eric you must have used your IT for straight runs along the sands I reckon if its still on the original piston and I dont think you would do that every w/e. Ozzie enduro's use vast areas of salt lake quite often amongst the scrub and wooded bushland, very hard work :-))

Actually, I raced it quite regularly at desert enduros during the eighty's, all the way up to 1987. After that it has been used a few times a year until now days it is used once a year at thanksgiving when we go to the desert. Today I would still take it anywhere and ride it the same way and not fear it frying.


Eric<>< :cool:

Eric you would love a 72 dt2 mx? I have a running almost complete one, just missing air boot would be easy resto. I ride a rt2 mx and wanted the 250 but never got around to fixing it up. Its not ready to ride with the bent bars, blown fork seals and a sprocket the size of a dinner plate.

hi Eric

Never fried our works one either but did regular ring changes and certainly one rebore that I recall. Wonder where it is now????? Obviously the factory marketed models under differing names as Australia only had MX'ers as competition machines, no lighting coils etc and were imported as a lesser performance bike to the YZ's. IT's came with a poor lighting system and could be licensed only for road use in competition.

We are getting some mileage out of this old post, yeah? I think dt2mx's and rt2mx's are seriously awesome machines. I think they were a much better "first attempt" say than the TM400. I actually like rt2mx's the best. Probably because they are more rare. I recently gave a 1973 mx250A to a motorcycle dealer buddy of mine. It was complete and original with the exception of '74 yellow fenders, an X-ducer silencer and S&W shocks(remember those?). Thing is, I don't care for the 1973 at all, just the '72. To answer your question, no I can't have anymore toys til I get some bills paid and a place to actually care for a vintage machine the way it deserves. But thanks for asking. If you have any photos, I would love to see it though. I used to have a YZ250A and when the crank cheeks came apart(they were hollow) I rebuilt and put a YZ360B motor in it and had a 360 before the 465....This is a real neat forum.....I Like It!!!

Eric<>< :cool:

I need to get it out of the shed and hosed off, maybe sunday take some pics. Im a big fan of the dt1s & rt1s and have lost some intrest in the dt2mx, the rt2mx is my favorite to ride out of all my old yamahas or my cz, it is dependable and fast the evil handling and crazy power hit make it a blast. for the last three years I have been building a rt1 mx that has gotten way out of hand I can send pics of it if any one wants to see.

I would love to see pix of the dt2, rt2 and rt1mx, I love those old bikes.

Eric

Have some pics wont let me post them :(