If the flywheel key is OK the ignition timing can't be all that far out. If you have electronic ignition plus the key is OK, it can't be out at all. Personally I think I'd rather use an ordinary automotive timing light so I can check everything at once, but then the first time you do it you have to mark top dead center on the outside of the flywheel. I just hate taking the flywheel retaining nut off to get a look at the key - and anyway I got in the habit of using a timing light.
