The rear-exhaust lower tappet cover gave me fits of frustration. The lowers are reproduction, and may be thicker than the originals? The covers are tight and close tolerance. I had to remove the rear cylinder a couple times, and fit everything. I used a 26" X 1.75 bicycle tire tube, and sectioned it for the rubber center dust covers . . . just like the old days of dirt racing!
Noot Sr. completely disassembled the original WICO Magneto, replaced the fiber drive block, tested it, tuned it - and now she throws violent, but controlled spark. These Wicos have a rotor, and function similarto an auto distributor - and spark single-fire. You need to hook the plugs wires on the correct cylinder, or she'll run really funny.