Yamaha's demise was giving up on the 2 stroke.
The 4 stroke was doomed in the mountains from day 1 IMO. Just too heavy. Works ok for some trail riders and utility stuff but . Everyone else stomped on them with 2 strokes while they gambled on 4Ts taking over.
It is interesting because they are the lone Jap dirt bike hold out to stick with some 2 strokes. Although the 2023 YZ250 is pretty much the same as a 2005.
I also agree with sheer. In the off road dirt bike world, KTM has gone from exotic to domination (in the last 20 years) by offering 2 strokes. Other Euro bikes like Beta, Sherco, and TM have also gained some traction by offering 2 stokes.
Meanwhile the Jap bikes are dying off, at least in the enduro scene by not offering 2 strokes. Would love to see MX rules updated to see a resurgence in 2T stuff. You can race a 450 4T against a 250 2T but IMO they should allow 250 2T or 4T to race in the same class.
