I was checking and found some info, but I thought I would post anyway.

85 ATC with the 86 ATC and 86 TRX

Differences in parts.. motor, swingarm, axle, brakes, etc.

 

the 85 250R has a 5 speed tranny and the 86 has a six speed tranny. don't know much about the trx.

 

Actually the 85-86 engines are identical and both are 6 speed trannies. the 81-84's have 5. How ever the rear ends between the 85 and 86 are different. The 86 has the same rear end as the 86-89 TRX. The axels are the only things interchangable on the rear end. The trx has a long rod engine, every thing else is the same between all the engines.

 

i have a good one but ill know the answer in 3-5 days, can you put a 86atc r bb stay on an 85? i also believe the 88 & 89 have the long rod. i think the tranny is geared a little different too for those two years

 

not sure what a BB stay is. can you clarify for me?


85 atc and 86 frames have some differences in bracing. the tank rubber straps that the tank sit on are different. the peg mounting points are a little different on the 85 to 86 atc. carbs are different. jetting is different in all three i believe even though the 86 ATC and TRX have the same carbs. there is lots of difference but the main ones i think have been pointed out. seats are obviously different on the TRX and ATC but even the 85 seat is shorter than the 86 atc seat.

swing arms, rear brake stay and bearing carrier are different on the 85-86's. the 86 atc and trx should be the same if not they are definately interchangeable....i had a trx swing arm on my bike for a while.

the 86 TRX also had a short rod. 87 was the first long rod i believe.