Hey guys, I'm super confused!

Up until today my understanding of the DT100 was pretty simple...I identify them mainly by which way the exhaust is routed. Pre 1977 it's the thru-frame exhaust and post 1977 is the side-frame exhaust. But what the heck is a DT100X then? Because I keep seeing these mainly in Asia, they look like they pre-1977 thru-frame exhaust models, but they seem to go up all the way to 1985? 

Can anyone help break it down for me please? lol

pre-1977:


post-1977


and the DT100X....

 

Yamaha produced many "old" models in other countries for decades... usually smaller displacement models. Features varied. Even in the US we got an off road RT100 in the 1990's which was pretty much a non-street legal DT100 from the late 70's. Be happy, it's one of the reasons parts are still available 50 years later!

Another example is the DT175 in the USA got an upgrade to leading axle forks in 1979 (along with frame changes and a new gas tank) . UK models did not get the leading axle forks... but they did get a square tube swingarm that we didn't get in the US until the 1990's RT180.

Makes sense! Thanks for clearing it up!

I've actually been swapping RT100 parts onto my clapped DT100 that was beat on like crazy by the previous owner. RT100 rear suspension/swingarm and front suspension bolted right on. I've also got some RT180 parts I'll be putting on one of my 175s as well. Definitely happy that they re-hashed those 2 bikes in the 90s...makes some parts a lot easier to find. Have an RT180 engine kicking around too, more capable porting-wise from what I understand and bolts right into a monoshock 175 frame.