Thanks for vid, can always learn. I had similar bikes to you, ZRX1100/1200's, ZZR12, ZZR6, ZX9R's. My 'New' YZF600 project had me stumped. Clicking Starter solenoid and Starter not turning engine. Replaced both, still same. Long story short, i had previously used instant gasket on Starter gear cover as no new gasket. I EVENTUALLY found the inner gear boss of the cover was crushing one of the starter gears, preventing it from turning. Home made cardboard gasket, and gear has clearance and back to normal. 1x millimeter made all the difference.