Stripped the head of my fun tin top down today (after a ringland failure), cleaned up the carbon a bit and spotted this rather excessive protrusion. Seems ripe for creating hotspots to me!


ST185 Valve Seat protrusion

Shocked no one had an opinion on this!

Looks odd are the other cylinders the same?

Yes, all the same. Wondering if someone has rwplaced the seats (badly) at some point.