Yep, ya got it, Darrell.. The plate absorbs the minute variations in engine speed that happen as a normal part of the engine running.. Like when the engine fires, there is a big pulse in the crankshaft which twists slightly then spins the flywheel at a minutely faster speed, then the flywheel slows down as the energy in it does the work of running the alternator, etc. and doing the compression work on the other cylinder.. It seems like a smooth rotation, but it is a series of fasts and slows.. The damper plate springs squish and un-squish slightly to absorb the pulses and keep the transmission from feeling them.. So .. if the damper gets loose or cracked, the thing can (not always, but can) give a once or twice per rev “clank” .. On a two cylinder motor with the crankpins set at 180 degrees (like your engine, I think), there can also be clank every two revs . This is the same as camshaft speed and can be mistaken for valve train noise.. Of course, the damper plate also absorbs the big things like when the transmission goes into gear from neutral, but its main job is the elimination of “chatter” during regular running. I am not saying that is what ya have, just noting ..that a busted damper can make a rythmic noise.
