Originally posted by doki_doki
what's the difference between the ostr r spec and the ostr e spec??? any significant difference in horsepower rating and cooling head design??? how about the carb???
If I'm not mistaken, R Spec is ROAR/IFMAR spec, which means cranckshaft could have bigger inner dia. (8mm), and turbo scoop can be big enough to come from inside hole.
E spec must be EFRA spec engine with crank inner hole limited to 7mm without chamfer and turbo scoop doesn't meet hole.
Sleeve porting, timing, and rest of engine must be the same.
AFM