gs550’s were a blinding bike in their day, however the hype drove prices up and they were no more reliable than a z550 or xj550, (not mentioning single overhead hand grenade honda cb550’s)
Everybody raves about gs roller bearing crankshafts but there was no jap four cylinder bike that took out a crank before the top end ate itself so there you go.
I had a brill gs550 rat bike that suited my riding style better than anything else i have ever ridden until the engine got too smokey.
I stripped it down and found two of the cam caps held down with wood screws and one of the gudgeon circlips was missing so the pin had scored the bore. It was fxxcked basically but until i stripped it down i thought it just needed a service.
When something is good its very hard to know when its so far gone its bad.