You'll have a new source for newly designed quality 4-stroke kits this summer.
I have spent a year working on making the venerable HS 142F 49cc 4-stroke a good alternative to a 2-stroke.
For direct drives the new actual Grubee Skyhawk 10G's with my design changes will be available in the states through other distributers than gasbike/kings, China Gas won't sell to them anymore.
I will have some direct drive kits but mostly my compact 'drop in' base with right side engine output, which is my baby ;-}
Dual Bearing mounted clutch bell and 20T T-belt pulley.
Dual Bearing concentric mounted 100T T-belt pulley on a freewheel bearing.
Super long output shaft with 9T or 10T 410 chain sprocket.
Adjustable carrier bearing on the compact 3-point base that includes a tensioner pulley on the base for direct connection a freewheel dual sprocket pedal system so both the pedals and the engine can use the gears without causing each other any drag.
Just letting you guys that will pay for quality if you can get it know I am going to fill the nitch with the help of my forum based web site for tech support.