Originally Posted by KnockKnock
A wealth of good info there, thanks Chainmaker. I got all happy when you said the HF engines will work (I've heard that a 79cc & [now defunct] 99cc are interchangeable), and then I realized that they sit backwards on the frame,
You can always stand up the HF 79cc vertically. Might fit that way since you can get it lower in the frame?