Ummm... I what u mean was A motor kit that is: -Quiet -Reliable for distance -powerful Than a 4 stroke is the way to go.
If I read correctly, you said u want power, and distance for cross country? All i know is 4 stroke engines will do just that. If you really want electric, then get a hub powered kit with a large ma/h battery.
Welcome to the forum. We have an all electric section that might give you the information you're looking for. Check here> http://motorbicycling.com/forumdisplay.php?f=56 to see what our electric power members are doing. Good luck and good to have more members from GB. Tom
They're about if you really want to chase them. They're not a true diesel, I think they're actually a midget hot bulb engine. Interestingly, UK moped regs state 50cc i/c engine for 2 wheelers, but trikes/quads satisfying moped tax/speed regs have a 4kw i/c or 50 petrol restriction. So you could run a 5hp diesel in a trike if you wanted to, thus giving you, in contrast to the Indonesian petrol tuk tuk, the knock knock.