250R TRX ATC Trans. compatability

[DIGGER DOG]

Im prolly gonna get flamed for this for not using the search,Oh wasss up everybody not been here for years .

Due to the availability of trans mission parts or lack there of,does any one know if the later year TRX trans.(main,counter,and all gears)are compatable with the 85/86 R?

Also could you also tell me the Years of the TRX engines that will bolt up to the ATC frame.
Thnx.

[Louis Mielke]

You're right you should have used the search because if you did you would very quickly have found out that they are nearly the same motor.
All motors are the same bolt pattern between the 85-86 atc250r and the 87-89 trx250r.
Someone more knowledgeable would have to confirm this but I'm about 99.1% sure the transmissions are identical as well. If they aren't then is a matter of minor differences and you should be able to swap the whole trans assemblies in the cases.

As far as availability? I would assume you're talking that you can't find your parts locally or new from honda because if you watch ebay or here on the boards those trannies flow like milk and honey. What exactly are you looking for?

[DIGGER DOG]

LOL Dunno yet I have 2 motors and they both run but I will split the cases on both when i get the $$$$ and do total rebuilds the shifter shaft on one has the shifter welded the other will prolly need shift forks and a few gears, I just cant remember at this point what gears forks/fork shafts etc.... are available from Honda and will have to wait till i go back to work on tuesday to find out Im actually a mechanic at a dealership was out in the garage smokin and looking at one of the motors just lookin for a quick answer cause im lazy I guess , I may end up selling all my crap anyways because the economy sucks and the dealer ship is being sold and may not have a job come feb. havent decided on parting out or what yet thanks for the reply.

[Eric250R]

Other than a slightly longer stroke on the 88-89 engines, they are identical. They all bolt straight in. I have the 88 engine in my 85 R. The clutch is also a little different on the 88-89, but once again, interchange. If you were going to use a crank assembly from a newer model you will need a spacer plate between the block and cylinder.

[DIGGER DOG]

Thats kinda what i figured Eric thnx man,

[KASEY]

Other than a slightly longer stroke on the 88-89 engines, they are identical. They all bolt straight in. I have the 88 engine in my 85 R. The clutch is also a little different on the 88-89, but once again, interchange. If you were going to use a crank assembly from a newer model you will need a spacer plate between the block and cylinder.

sorry,,a little correction needed,,,, the 88-89 has the same stroke as the earlier motors, and if you use a later model long rod crank you don't need a spacer plate if you use a later model piston with it,

[Dirtcrasher]

^ You'll be telling guys that forever Kasey :lol:

PS - Lou, I just used the search feature searching for my head stud repairs and searched "threads started by Dirtcrasher" NOTHING, NADA,ZILCH. I'm trying not to tell people to search anymore, it rarely works.

Easier to find in my inbox.......... Apparently the software patch is still not available?

[KASEY]

You'll be telling guys that forever Kasey

i guess its just something that will always exist, i guess thats why i am here,,, :-)

[Eric250R]

sorry,,a little correction needed,,,, the 88-89 has the same stroke as the earlier motors, and if you use a later model long rod crank you don't need a spacer plate if you use a later model piston with it,

Oddly, right after I made that post, I asked myself if it was the length of the stroke or the placement of the piston pin that made the difference. I was sure someone would step in and clarify. Thanks.

[Eric250R]

sorry,,a little correction needed,,,, the 88-89 has the same stroke as the earlier motors, and if you use a later model long rod crank you don't need a spacer plate if you use a later model piston with it,

Wait, now I"m confused. If you use the later model crank and rod, wouldn't you have to use the earlier model piston if you're not going to run a spacer ? Wasn't the pin height higher on the later models ? ....my brain is melting.....lol

[Dirtcrasher]

With the pin higher piston on the longer rod, it's the same as a lower pin piston and short rod............

[Eric250R]

Thank you sir....