Home › Forum › Ask A Member › 1972 johnson 4 hp bear to start › Re: 1972 johnson 4 hp bear to start
check the bottom of the flywheel on the original for wear marks, was the dragging/scraping noise consistent during the entire revolution or only intermittent during 1 part (or 2) of the revolution?
The reason why I ask, is that when the magnet passes the coils, you will see the mag plate jiggle, which can account for the scraping noise. If there is slop on the mag plate than it may be slightly tilting toward the magnet as it passes by slowly and dragging.
When the flywheel is turning 1000RPM, I would suspect that magplate is essentially ‘floating’ or in dynamic balance since the magnet is passing both coils so quickly that there isn’t enough time for it to slop/wobble and rub.