Xr100 Engine For Sale Is There A Difference In The Engines From A 86 Honda XR100 & 2000-present Xr 100?

Is there a difference in the engines from a 86 honda XR100 & 2000-present xr 100? - xr100 engine for sale

In the experiment, Honda XR100 motor for my mod 1986 and I can only find mods for 94 and up XR100. His attitude is the same only not sure of their engines going.