Originally Posted by chrisr
IMO if you go from a 750 to a 650 and it makes it more peppy than the 750 was just to much. Since it worked for TOD it may work for you. I had tried a 650 on mine and the 750 was alot more responsive. It all depends on what your engine likes. If you have access(friends etc) to one of each, try them and see which one works better. I may have had more compression and more flow than what you have.
By the way TOD, I like the avatar.
WHAT HE SAID . Always better to test before you buy if you can.
And yes the reason the 650 was better for me was the 750 was just too big.It was a 9:1 motor and the 750nhad the 50 cc pump on the rear and it just would fall on it's face when you floored it...the 650 brought it to life.