Originally Posted by Egor
Looks OK for the break in period, should be rich. Those spots on the piston are where the Scavenging ports are in line with, and as the blast of mixture comes out it washes the piston off. That should be a good spark plug NGK, and I like that heat range. Have fun, Dave
Not being picky or anything, but if those two brown bits are the port locations and those are the important things that make the motor go - why are they such different sizes? or am I missing something obvious?
It does look a little damp in there - mine when I shine a torch down it is pretty much dry as a bone inside - which is probably a little to do with the 50:1..