Take bung out of gearbox and set flywheel to tdc mark check cam mark on sprocket and check where rotor arm is in relation to small mark on the dizzy if cam mark is in the right place and rotar arm is there or there abouts get your timing light and adjust dizzy to 6 btdc mark on flywheel whilst reving engine 2500. I found it best to set cam with OT mark on small plastic cam cover
Hope this helps