Vintage Dirt Bike Q & A

Hi,i am trying to build a honda cr scrambler can anyone tell me if a seat from a 1974 mt250 will fit on a 1975 cr250m1 frame,also will all the internal engine parts from a 1974 mt fit into the crank caseings off a 1975 cr250m1,i would be very greatfull for some advice.Shaun.

My MT250 has a seat that tilts up on one side using the ignition key on a lock. It will not work on a 75 CR250 since that seat just bolted on to the frame. The MT250 motor is different than a 75 CR250 such that only the clutch, clutch cover, shift shaft, and maybe ignition cover will swap. The cranks use different lenght rods. The MT250 tranny has a raised surface on the output shaft which will not work in the CR250 cases, unless you grind it down like I tried once. If you do swap trannies use the entire MT tranny since it is a spread ratio compared to the CR and shares almost no gears.