Gs550 engine problem

[zakb2010]

Hello everyone, long time reader, first time posting. Love the forum, tried searching but need some direction. My buddy was looking at getting a bike and I found a 81 gs550 that we ended up picking up. It had an oil leak from a stripped drain plug so we stopped and checked/ added oil twice on the hour and a half ride home. Long story short: buddy forgot to check the oil(almost all drained out), rode it around the neighborhood 30+ min and parked it(he said it "sounded fine") I drained the oil(less than a qt, still looked pretty good for what was left), changed the filter(small collection of alum shavings in filter cavity) and filled it up with rotella 15w40. Started it up and I heard "clack clack clack" coming from what I assumed was the top end. Sound varied in volume with the rpm's. So we ended up pulling the head and didn't find anything obviously broken or damaged(cyls have good surface, pistons and Valves dirty but appear intact) Going to go to the bike later today to get some pics. Please, somebody give me advice on where to go from here. Will post pics soon. Sorry for the wall of text but I am desperate and needed to lay it all out.
Thanks, Zak

[Nessism]

Since the top end is off you may as well go though everything and check against the factory manual service limits. Remove the valves, inspect the valve guides, inspect the valve springs, etc. If everything checks out, put it back together with fresh OEM gaskets and seals. Hard to say what could be wrong based on your description, but running the bike 3 quarts low on oil is not a good thing.

[BassCliff]

Greetings and Salutations!!

Hi Mr. zakb2010,

Welcome to the forum. You'll find additional resources in the "mega-welcome" thread: New Members, CLICK HERE!!

Thank you for your indulgence,

BassCliff