I have wanted a Japanese trials bike for a long time. I've located a 1976 TY250. It might be the one to restore. It's biggest issue is someone has swapped on a larger seat. I'll be looking for the correct seat.

The Ty250 I found included an extra engine. It looks like the one still on the frame except the head has radial fins. I suppose it's a 250 from another Yamaha 250?

It looks like what I see listed on eBay as a DT250 or YZ250.

Edited January 14, 20251 yr by Papa

Where did you happen to come across the bike? I'm restoring a 1974 (or 1977, I haven't been able to figure it out yet) Yamaha TY250. I accidentally put a large crack in the crankcase cover and there was already a large crack in it as well, so I was wondering where you found the bike to see if I might find a replacement cover there. 

6 hours ago, Papa said:

The Ty250 I found included an extra engine. It looks like the one still on the frame except the head has radial fins. I suppose it's a 250 from another Yamaha 250?

It looks like what I see listed on eBay as a DT250 or YZ250.

What does the rest of the extra motor look like? The DT250 radial fin head motor looks quite different to TY250 motor in many ways. Shape of engine covers, location of kickstart shaft, length of motor. It's a popular thing to fit the DT250 radial fin head to TY250 twinshock motors.

17 hours ago, Striker said:

Where did you happen to come across the bike? I'm restoring a 1974 (or 1977, I haven't been able to figure it out yet) Yamaha TY250. I accidentally put a large crack in the crankcase cover and there was already a large crack in it as well, so I was wondering where you found the bike to see if I might find a replacement cover there. 

It's local to me. If I buy it and have parts to spare I will let you know.

This is the seat I use on mine, they also have the mounting brackets available

Trials Bikes :: Frame & Suspension :: Seats :: Yamaha TY250 Twinshock Standard Seat