I'm one of 6 or seven owners of JH250E5 cruisers in Harare, Zimbabwe. I've reduced the rear sprocket to 29 teeth to give a theoretical 140kmh @8500rpm but need a bit more torque. We're at 1500m above sea level, so I need smaller main jets than the 98s fitted, but can't find anything here. Has anyone played with one of these to get a bit more power? They are a clone of Honda's CB250, which is rated at 15Kw - but theJialing version only produces 12Kw. If no-one's attacked their motor yet, I'll carry on and keep you informed of progress.