Re: Mag side engine seal.
Impact wrench. The quickest and easiest way to loosen that nut. If you don't have access to one then put a socket on a ratchet and smack it with a soft head hammer.
Once the nut is off the next challenge is getting the magnet (rotor) off the crankshaft. Here's where you'll want to be careful. The crank is only about 5/16" in diameter where the rotor rides and it can be bent if you pry too hard on one side of the rotor. There is a woodruff key and sometimes it can give you problems getting the rotor to come off. I've found the perfect puller for the rotor in a faucet handle puller tool from Ace Hardware. It is thin enough to fit behind the rotor and pulls it off easily. After the rotor is off check the seal behind it. Its not uncommon to find them not seated correctly in the bore. If the seal is not damaged or worn you might be able to press it in until it fits flush or the better route is to replace it with a new one. Many of our sponsors carry new seals. Use a socket just a shade smaller in diameter than the seal and drive it in until it is flush with the case. Lubricate the new seal and crankshaft with engine oil before assembly. Good luck. Let us know how you make out.
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