make sure timing set good flywheel have no key way leave flywheel nut loose so you can move flywheel take out sparkplug use long screwdriver to touch piston top dead (tdc) centre once you find tdc move crank shaft to move piston (anty clockwise) down 2mm before tdc you should have aleady set point gap now with piston 2mm before tdc turn flywheel to make points just to start open now tighten nut for flywheel
may be when you change coil you not time it proply
