Been abusing the Goo5e (goose;-)) lately and decided to give a little TLC. Was a little snatchy on the throttle opening closing recently.

I keep my valves close to .1mm, one had gone down to .09 after 14 k KM. Nice to see them so steady.

Plugs were looking waaaay to light for my liking, definitely indicating lean. This with the snatchy throttle makes me think lean / intake leak.

While I was in there took off the airbox and the carbs to look at the intake boots. The screws holding them in had low torque, must have loosened up over time. (noticed that all 4 screw holes in the head had been helicoiled in the past. How in the hell did someone strip them with just a screwdriver!!!!!), helicoil is probably why there was no blue Loctite on the screws.

The o-rings in the boots are normally CS (cross section) of 2.4 mm but they had been flattened over time to around 2.0mm. I'm sure I was leaking air there. 

So just a reminder before you look at jetting carbs make sure the intake tract is in good nick!, I'f id been trying to work on jetting in this state i'd have been on the road to one hell of a hiding.

I'm considering new carb boots, mine are old but still "softish", though a new set will last the life of the bike.

Retorquing the outer head bolts was difficult, they get baked on with road grime etc. had to take them off one by one and run them up and down and can clean the threads  to i could torque them reliably. (always mark head bolts nuts before retorquing to see what is happening)

If it's an American GS?

You can Safety go up one size on the Pilot & Main Jets