I want to put a 450 ex engine in my 250r quad any tips on what needs to be changed and what needs to be done would be gret thanks.

 

a 450r engine or 400ex engine that you bored out?...you will need to take the 450 engine and build the frame around the engine to make it fit correctly.

 

it is a 450r engine

 

Why would you want to put a 450R engine in a 250R frame?

 

Its my buddys quad he wants to take the 250r engine out cause it literally vibrated his bike apart and he wants the dependability of a 4-stroke he would prefer a 450r but would settle for a 400 the thing has been nothing but problems since he got it

 

It would be best then, to just buy a used 450R or 400ex.