Logo

flywheel magnets repair

nicknack2

Regular Contributor
Guys I'm about to take the flywheel off my Johnson 200hp to rapair loose flywheel magnets, you guys got any things in particular to watch out for before I do this??? You guys got any ideas on a homemade tool to prevent the motor from turning while trying to get the flywheel nut loose?? Also what you guys recommend to clean up the surfaces to be glued and what kind of material to use to glue together?
 
Ya , you are going to need a flywheel holder, when you remove the nuts you are going to have to use a puller to remove the the flywheel. Make sure the bolts are all the way threaded in the flywheel so you dont rip the puller out of the threads. crank and tap the puller with a hammer and it should pop off. I usually let the nut soak with PB Blast too. your going to have to remove all the old magnets then sandpaper 80grit clean. I use brake cleaner to make sure I have a clean surface. Read the instructions very well a couple of times to make sure the notches on them go in the same direction and you use 7/16ths bolts as spacers .
 
In place of the 7/16" spacer bolts, I've always used short pieces of 3/8" fuel hose (the height of the magnets). This avoids attracting either magnet and keeps the spacing uniform.

Make sure that the flywheel and crankshaft tapers are absolutely clean and dry when installing.... and be sure to torque the flywheel nut to 145 foot pounds... anything less will result in having the flywheel key shear.

The tool to be used to hold the flywheel is actually a tool that auto mechanics use to turn the flywheel when installing a pressure plate for a manual shift transmission clutch (Pictured below), available at any auto parts store. It's usually referred to as a spanner wrench.

Spanner-2.jpg
 
Last edited:
In impact air gun will loosen the nut also. The magnets have a polarity to them and must be reinstalled in the correct direction. So mark them with a paint pen before you remove them.
 
Back
Top