Hi Everyone,
I was using a 56 tooth rear on my Q-Matic, and the 2.5 HP Honda motor.
The Greyhound powered bikes [I rode both of them] pulled strong at the bottom of the torque curve, but the Honda [HS also] revs so quickly it easily out distances the HF motor in short order.
The Greyhound is a great choice for "low speed grunt", and like Kilroy stated would be great for hills or heavier riders [or both] crusing at lower speeds. The Greyhound makes its HP much lower in the powerband, whereas the Honda or HS motor peaks at a much higher RPM.
It was nice to test the 79 CC Greyhound, and the 49 CC Honda with the same drive system to arrive at an honest comparision. All 3 versions of the 4 stroke motors worked well and certainly offered a different approach. During the Lewes event we also discovered the Greyhound liked the un-restriced exhaust [EZ Flex pipe] system.
If anyone has the remains of an earlier kit [tank, throttle, drive sproket, etc] the HF motor can be hooked up to the Q-Matic drive, and all that is left is to fabricate a motor mount, and go riding! It is necessary to mount the motor slightly higher in the frame because it is longer than the 49 CC 4 stroke motors, but looks great as an in frame motor.
Have fun,