1986 atc 250r transmission upgrade?

[mcgyver331]

I have just picked up my 2nd atc250r parts engine, I am catalogging all the parts I've purchased and I have found that one of my shift drums are thinner and also found an extra shaft with 3 forks on it.

I am confused, It looks as though (from other pics) this thinner one is from a banshee or trx250r but I dont know.

Is there a site that describes in depth the 250r trans? Or can anyone shed some light on my confusion.

[hrc85250r]

all of the trannies are the same, everything is interchangable. the wide shift drum could be from a banshee, ut the trx drum is about half the width of a banshee.

[mcgyver331]

Hey thanx for the reply, I have catalogged all the parts needed for the buildup of the 250r motor, If the bearings are all good not too loose and none grinding I should only need oil seals and gaskets?

[TeamGeek6]

Replace at least the crank and counterbalancer bearings. WAY too much work to go that far adn not change them. Side play should only be about 15 thousandths of an inch on any of those bearings.