It's probably been talked about before but I only have built 1 bike a few months ago I'm very happy with it so far I've done about 500Km I live in Ireland so it would have to be shipped from USA/China. I'm thinking of either modifing the bike or selling this one and putting a freewheel Crank. Are there any good ? If I was to sell my 2 stroke I might go for a 4 stroke with the freewheel crank are there kits for the engine or do you buy the kit and mod the bike (to fit freewheel wheel crank). Does the kit have to be modified to fit the crank ?