Yamaha TRI-Z 250 Tech Question

[Rider414]

After some research the 85 and 86 TRI-Z 250 have different carb jetting specs.

Question: Are the carb's different at all or just different jetting? Anyone know specifically why Yamaha did this? :wondering

[dave ytz250s]

Alot of different stuff, I think the carb is the same casing but have different jets, needle, clip position, nozzle, slide. They changed the air intake tube, carb, reed cage, reed valves, piston and rings, ignition coil and cdi. Aftermarket reeds and piston/rings are the same for all models so the difference should be minimal and I think both carbs will work on both models as long as you change the whole setup, not only the jets. I think this was for a performance upgrade but not sure if it made a big difference. They also changed and alot of stuff all over the trike.