RE: OS 91 or Evo 1.00 for Little Toni?
I agree with Gar there.... nothing wrong with the ST90. With the rebate offered at the moment, its a pretty good value.
The OS91 is capable of a bit higher rpm, when using at tuned exhaust system. The ST90 with a tuned exhaust is pretty good too, but with bigger props, and a bit lower rpm. The Evo, from what I have seen, is somewhere in between these too.
The ST and OS worried of the past are pretty much just that - passed. Most problems these days result from using the wrong exhaust, or poor tank/plumbing installations.
Its kind of a toss up.