It sounds like the flywheel is rubbing against one of the coils…….and thereby moving the mag plate as the engine is pulled over.
Check to see that the coils are positioned correctly …..they should line up with the boss on the plate.
There’s a tool that helps with this…..a coil positioning ring…….but it’s easy enough to do without it.
Richard White sells the tool. https://richardsoutboardtools.com/product/coil-locating-ring/
