Throttle stuck?

[EvMachina]

I just finished putting my R1150 Rockster back together and it was riding fine for 10 miles or so when suddenly the throttle has gone out of control.

The engine surges as if I've got the throttle completely extended and I'm not even touching it. Once I fire it up in neutral the engine will surge up to the red at which point I promptly shut it down. Any ideas what could cause this?

Thanks

[bikerfish1100]

check throttle cables on TB pulleys, look for stones in pulley wheel, check cable end above wheel.
follow the general principle of checking the last thing you changed/worked on.