Just pulled my 1397 out of my street bike to put in my race bike. The engine ran great, but when I pulled the throttle bodies and exhaust I looked at the valves. Most of the exhaust valves looked pretty /chambers looked pretty carboned up like it had been running rich. A couple of the intake vales looked like they had a little build up as well. Like I said the bike ran great, but wondered what the best way to clean up the vales a little without pulling the head apart. Seafoam maybe? I have never used the stuff but heard great things about it. Thanks guys