It's a long time ago so I might be wrong.but I put a bultaco pursang motorplat ignion on my bultaco trials bike in place of points and there was a hole though flywheel and back plate that you could put a rod through to line the up in the right place then take the flywheel off tighten back plate then put flywheel back and tighten sorry if I'm wrong as I said it was a long time ago good luck