Hi Terry,
In my experience of the GS motors, the exhausts close up and burn valves.
I've never seen a GS motor where the clearance gets wider? (unless oil was filthy and cam/cam bearings wore out)
As the valve face and seat wear, valve sinks into the head, the clearance is reduced.
Usual sign is real hard starting when cold but runs OK hot
I would always set tappets at 0.004" in and 0.005" ex when someone brought a GS in complaining about hard starting from cold, sometimes it was caught early enough and the valves wold re-seat properly
We only charged a pound each exchange, (it was a long time ago though, 25~39 yrs
![Wink ;)](http://forums.sohc4.net/Smileys/default/wink.gif)
)
10 dollars is a rip off as they are rarely using Suzuki shims.
If dealer has been doing GS motors from new, probably has several thousand 270 shims by now
![Grin ;D](http://forums.sohc4.net/Smileys/default/grin.gif)