new motor

[chris450250]

Hey guys i am rebuilding my 1988 250x and i want to replace the engine... i want to use a xr650r motor or a 350x motor does anyone have some advice on which would be better or any pictures of thier own conversions

[Project300EX]

I may be wrong, but I don't think an xr650r motor will fit without major frame modifications. The 350x is probably one of the most popular 300ex/250x swaps.

[heath720]

i have a fully built 350x motor. this thing is wicked fast. it will keep up to stock 450s. let me no if ur interested.

[chris450250]

hey tell me about your motor.. how many hours? who built it ?some pictures and a price would be nice thanks man

[heath720]

its got about 10 hours since rebuild. a guy in green bay, wis. built it. it does have a cracked side case from where the chain slipped but it can be replaced for around $50. $1000 negotiable.

[heath720]

the cracked side case.

[chris450250]

no thanks i think i am just going to modify my motor thanks alot though

[JIMFROMTEXCO]

the 350x swap is super simple.. you have to remove about 2" off the rear upper mount and make a spacer...

i bought a complete trike for 500 and it ran i was able to use a spacer that was in the trike to mount the motor.. and the whole rear end off the 3 wheeler bolts to the 250x easily.. the swinger is about 1 1/2" longer and the axel is 2 1/4" wider