I have 2 rotary valve yamaha motors i think these are 2 of 4 in the states we use to homologate motors for WKA and yamaha never too these back they are brand new never ran the reason they never came into the states was Yamaha quit building them and they had more horse power than komets or corsairs.
Had 2 of these motors,with piston port cycl. that Gary Hartman built back in 1980,probably won ten thousand dollars street racing. Ran c open at Greenfeild In. street race using only one motor and only had one guy beet me.
They was really fast.. Had trailer stolen at the end of the 80 season and never saw them again. Wish i had today they would be killer on Vintage kart..
I still got these 2 and people are e-mailing about them have had some pretty interesting trades offered, would love to trade them for a project enduro or sprinter twin been looking for a mean machine for my father or old hornet like he use to run back in the day......
I know a guy that has a Hornet enduro,don't if he want's to sell . I will check with him, i don't know if he would want to trade but i will check.
E Mail at email@example.com and i can get back to you direct..