Why do the YS engines and especially the DZ's produce more smoke than other 4 strokes?

Thanks

Because the type of fuel they must use contains more oil.

Thanks Dave,

I thought maybe due to higher compression, hotter exhaust creating cloud effect, or something like that. Saitos on 20/20 never seemed to produce the same smoke (or power) as the YS

HP is heat. They do run hotter and more powerfully than any other 4 banger. That's why we recommend the fuel we do.