The Official 084 Thread

[Dennisthemenace]

I have 2 084's as projects to rebuild that came with a spare flywheel and numerous odds and ends. Some of the fw's have dual key ways, one does not and my personal 84 has the single.
Can anyone tell me what the deal is? Something to do with the coil I guess?
Not expecting the dual kw I did not notice which was in use on disassembly.