1985 atc 250r has KA code with either 2 or 4 on crank, 1986 atc or Trx has an HA2 or HA4 on crank and 88-89 has HB9 on crank. I could be wrong and there may be other codes but will check cranks in morning.

 

Thankyou, I just ordered a hotrod complete bottom end rebuild and I guess wanted to make sure this was a 88 long rod engine in a 88 frame. Since I ordered a 88 trx250r hotrod rebuild since this is an 88, let's say it in reality is an 86/87 short rod engine, am I good to install this 88 crank and 88 wise piston then?

 

Looks like 85-87 atc used this long rod crank also
From what I have found this is a 88/89 long rod oem crank.

 

Yes...Long Rod for 87-89. Short Rod for 85-86 ATC or TRX250R.

Carlos

 

Thankyou