250t alum frame build using rmz frame

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6/18/2018 11:10 PM

Ok i've seen a handful of 2 stroke builds converting to af frames. Im looking to do this but im having trouble sourcing a rm250.
i have a 13 rmz250 im considering not rebuilding

has anyone used another brands engine in another frame? i can find a handful of honda and yamaha's from the early 00's all day long


"If you feel in control, you're not going fast enough" ~Mario Andretti

6/18/2018 11:30 PM

A lot of the swingarm pivot hole/width on the engine cases are going to be different from manufacturer. Which will make you have to come up with decent fabricated spacers to work inbetween the swingarm and frame rails, decent amount of work and needs to be spot on. I'd try to stay same brand. On mine, the old kx5 cases fit perfectly in the 09 frame/swingarm, but the cases had to be drilled out a handfull of mm to accept the latemodel swingarm pivot bolt.


-'09 KX500AF

- '19 KX450F

6/19/2018 12:13 AM

Yep... RMZ250 frame with YZ250 engine. Photo


6/19/2018 12:15 AM

Spacers for the engine/swing arm pivot are simple to make if you have access to a lathe too. Photo