I heard that using anything but the crank bolt or a starter button is improper. Will using the PS bolt be harmful? I'd like to be able to adjust the valves by myself, and not having to get under the car and back up again a million times to see if the cam lobes are up would make it a much more enjoyable maintenance task. The starter button method never seems to work right, I can never do it to where the cam I want to point up is pointing up. I always overshoot. And besides, how would I keep the engine from firing?

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)