RE: Moki 1.8 performance
Not Sure about the 2.1 but my 1.8 was running very rich at 7100rpm's. I'm quite confidant that the 2.1 will do the trick for you and then some. I have heard of a few guys running a 20x8 on the 1.8 but most of the advice I've gotten has been leaning towards the 19x8 size prop. Good Luck!
Loopman [8D]