Originally Posted by bucketboy
OK, so KV rating is useless for a camparison, can watts be used as a standard measurements?
No, as the same issues apply. Crank the timing up and you'll get more peak watts, but at the expense of low-end power and current draw. That's if the watt numbers are even from a dyno and not just invented.
The cheapest and simplest way for most people to find out if a motor is decent is to ask the people who are winning at the tracks you race at, in the class you race. In reality there's not much between any of the top motors, which is why you see all of them up in the A final at some point or another.
If you want a true comparison "number", you'll have to build a dyno and buy/borrow a lot of motors, and even then you end up comparing power curves which isn't always simple.