No... The 250EX is shaft drive the 300EX is chain... The 250X will fit
the 250x is a chain drive also its was the same quad as the trx300ex but has the 250 bore and kick start the 300ex was the new model that came with bigger bore and electric start. he's stuck the trx250ex is shaft drive and swingers between the 300ex 250x or 400ex will not interchange
