Could go either way.
I just tore into my 1150 for a new clutch and a leaking right head gasket. I figured while I've got one head off, I'll pull the other and clean the carbon off that one too.
I'm glad I did, I found a valve that was burned and not seating properly.
Prussian Blue tells the story:
The valve is toasted and is only a matter of time before it left me stranded somewhere.
This GS has 103k miles.