could not hardly believe my eyes, have several 480's, to remove one of my flywheels I would loosen but not remove the flywheel nut, hold the saw off the bench with pliers on the fins (two pairs) & have someone tap the flywheel, the seals don't really have pullers, if you break the crankcase in half they will punch out, or you can try a self tapping screw in the outside and pull on that... good luck!
my first impression is an intermittent electrical short under load, even new plugs out of the box are sometimes bad, if this were my challenge I would start at the plug and work back from there to the module...good luck
if it won't pull right off after removing nut(s) from the cover studs the brake is most likely on and do not force it, try to reset the brake first and see if that helps
I have two mowers, both Kohler, one has a regulator on the engine cowl, the other I bought used and abused, had a burnt out rectifier/diode and I picked one up at radio shack and soldered it in, charges fine now, it is in a wire very nearthe oil filter, hopw this helps, the other one was completely missing and therefore impossible to find, some research and a you tube video got me on the right path....
the 'key' is part of the flywheel casting, might be sheared off and you are unable to see it...the ignition modules do go, when ever they want to, test it against a known good one if you have access to one...also shorted (chaffed) kill wires will prevent spark
when viewed from the starter side, the vent is located very near the center of the tank no doubt out of sight unless the tank section is removed from the saw, try looking slightly to the left of the fill cap, but very deep into the center of the saw...
that looks spot on, worth noting without an electric clutch for the blades, on the same deck the setup is slightly different. make sure your pulleys are not eating the belt.....
seems you answered your own issue, if removed withthe brake engaged, it will never go back on without being reset, if forced you will ruin the brake band, try putting it on the bar mount studs without the bar and chain on and see if you can use the brake handle to reset the band, it is a bear but can be done...if it won't then the clutch drum should also be removed so everything will line up to do the reset, then reassembled....
the 372 has been the standard workhorse for more than a decade, a very good saw. the 562 (autotune) is new technology (computer chip) and a complete redesign, balance wise and work feel. in a race crosscutting the 372 would probalby have a slight edge, it is 10 cc's larger in size.. hope this helps
if you are describing a "stuck piston ring" you may be able to free the carbon buildup with a product called "Seafoam" available @ various places, would suggest a compression test to determine if this is actually the problem, to try a 'seafoam soak' bring the piston all the way up in the cylinder with the plug removed and put a tablespoon or two of seafoam in it and give it a chance to work, say overnight...will smoke awfull when started but should clear up... if that is the problem..
without seeing the clutch, I would say take it off and look for a part number stamped on it somewhere..
one end of the spring goes into a lever that pivots on the deck, the other attaches to a post like looking thing, sort of a large bolt that the spring tension works off of.
any dealer will have the correct size, use a very thin wire to 'marry' the new to the old one and use it to pull the new line into position..good time for a new filter too - hope this helps...
I know what you are going thru, try supporting the cover independant of the saw and using the brake handle to reset the band, it is a bear sometimes, you can do this - will take some imagination, and next time will be 'fondly remembered'....
an inspection of the saw seems to be in order, start with the fuel line - looking for a tear near where it exits the tank, next a stopped up filter, next a compression test... hope this helps keep it simple and the solution will present itself....