Jo...really, do yourself a favor and figure out a way to make your life significantly easier by mounting a pedal crank and chain on that thing! In my hunble opinion, (having owned six Magnums and 1 Maxi), one of the absolute WORSE things you can do to the bike is remove the crank/chain system! There is LIMITED pleasure to be derived from pushing a Magnum down the street (or UP a hill so you can pushstart it DOWN) and I don't think the Maxi is a vast improvement. Frankly, it was singlehandedly enough to limit my riding of my Magnum LTD. (And no, I didn't remove it; it came like that).
It would also make your other diagnostic jobs somewhat easier.