85 should be a 225DXN or a 225DRN, depending upon if it has reverse or not. In either case, the motors were basically the same, so you are safe buying that piston and rings.
Hey... welcome to the board!
Bruce
PS... the last letter is the year....
K = 83
L = 84
N = 85
S = 86
'85 ATC350X - "Showgirl" '86 OEM plastics/Fork boots, Rear Axle/Rotor/Hubs, Hondaline Fender stabalizer/extender, Speedo/Tach, Tank cover.
'86 ATC350X - 'Go-Go Girl'
'82 ATC250R - 'California Girl' - Progressive springs F and R, Hondaline HL Guard, Fairing and Speedometer.
'82 ATC250R -'Snow Bunny' Ice Racer, Very Clean, Hondaline Fairing, custom FT tire, will put in the 300R motor
'70 US90 'Ol'Girl" - Aquarius Blue... all original seat and tires. Resto project in the future
'85 ATC250ES-'Workin' Girl' CMP Footguard, Hondaline Mudflaps, Speedo, HL Lens, Block Heater, Work Light, Foot Peg Covers and Cooler Rack
'85 ATC70 - All Original
'84 Yamaha 225DX - Durablue +3" axle, DR motor, New Plastics, Foot, Hand and HL Guards.
'85 Yamahauler - Gun Rack & 'Nerf Bars'
'85 Yamahauler - Nearly together and restored
'83 Suzuki ALT125 - Pieces
'89 Suzuki LT-4WD - Token Golf Cart