i run an absolutely standard b175 engine straight from a mot'd road bike plus electrix ignition in my drayton, its flexible forgiving and more than enough to haul my 18.5 stone up anything , rides fantastic.. all weekend at the captains trial i ve been asked , who did your suzuki piston who built the engine, which barall did you use, whose gears have you got, what airbox is that ( its a standard b175 inlet rubber with a mini moto foam filter ...2.99) dont waste time and money..