xr100 motor sl125 frame?

Does anyone know if the xr80/100 will fit the sl100/125 frame? If so what are the modifications needed if any?

The 100 should be close to a bolt-up, except for maybe the top motor mount. Lifan makes a 200 CC engine that they claim will go in both SL & XR. I think the 80 is smaller.

A XR100 is very different than the SL100. Maybe with major engine mount mods.


My brother put an '83 XL100S engine into a '75 XL100 chassis. (Well, it was what he had, at the time... :-))

The '83 motor should be VERY similar to your XR engine, and the '75 chassis will be very similar, engine-mount-wise to the SL. The newer motors are a bit smaller all around than the older motors, so you'll have plenty of room to work with.

It was very nearly a bolt-in, in a do-it-yourself, cheap bastard sort of way. The top rear mount just required a few washers as spacers to get the sprockets to line up. The front motor mounts were just a few pieces of bent steel drilled to mate up. 1/8" plate bent with a hammer and a vice, cut and drilled to fit.

Done and done, and that was nearly 20 years ago, and he still owns and rides the bike.

Good luck with it.


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