Identifying year of motor, 86 or 87?

[Blown 331]

I have a 1985 ATC250R and I bought a motor for it that came out of a 1986 ATC250R but the guy said he got it from an 87 TRX. I'm going to order a piston from a 1987 but just incase the motor is an 86 what would happen? I'm guessing it will be obvious like the piston comning out of the jug or something like that? Also will my 1985 cylinder work on a 1987 motor as long as I use a 1987 piston? I know all that is confusing so hopefully it makes sense. Thanks in advance.

[Dave83]

Your 85 cylinder will work on any year R motor.The difference in the 85-86 motors and the 87-89 motors is the rod length.Check the rod and look for #s.HA-2 is the long rod 87-89 set up and HA-4 or KA=4 is the 85-86 setup.HA-2 uses the 87-89 piston and the HA-4 or KA-4 is the 86 piston.

[zedicus00]

all jugs work on any yr watercooled R. yes, if u used the wrong piston on the wrong rod it would iether come about 5mm out the top of the jug or be about 5mm from the top of the jug at TDC. iether of thouse an you know you hav the wrong combination. if the piston comes out of the jug just get a spacer plate for the base.

[baker250r]

was the 88 bottom ends black and the 86's silver? im kinda wonderin this, cuz i got an 88 frame, and i think it might be a whole 86 bottom end, cuz i went to rebuild it and found ou i got a short rod.

[1988R]

Originally posted by baker250r
was the 88 bottom ends black and the 86's silver?

something like that gray,silver what ever you want to call it
Look where the front engine mount bolt goes though the cases. If the cutout is about 1 1/2" the bottom end(at least the cases) are not an 88-89. The 88-89 the cutout is almost the entire length with the exception of about 1/2" on each end

[CHAR250R]

1986 motor s/n: TB06E-1000014 to 1021097
1987 motor s/n: TB06E-8000015 to 8008442
1988 motor s/n: TB06E-8100014 to 8109454
1989 motor s/n: TB06E-8200001 and up

This should help identify your motor if it's out of a 4 wheeler.

Originally posted by baker250r
was the 88 bottom ends black and the 86's silver? im kinda wonderin this, cuz i got an 88 frame, and i think it might be a whole 86 bottom end, cuz i went to rebuild it and found ou i got a short rod.

that sounds personal
:D