Why avoid STS at all costs? I've got the STS .30 in my buggy and it rips. Holds revs good and is fairly easy to tune and has heaps of torque. For AUD$250 you can't go wrong. I also have the one of their .12's and it's been great. Very reliable, plenty of power and fuel economy isn't bad. I've ran it for about a year now and it's still got a fair bit of pinch left and no slop on the conrod at all. The only thing i've had to replace are the o-rings in the carby and that's after countless litres through it. For the price they are great motors or at least they are my experiances with them anyway