Although scored visibly, this cylinder came from a working engine!

I put these photos so you wont panic and jump to expensive conclusions if yours looks as bad, since the replacements are rare/expensive from the dealer.

note

the deep score below the plug was probably caused by incorrect piston fitting i think the wrong way round? I will look into this - the manual shows the piston ring-dowels nearest the exhaust port, but i think it should be the other way round?

the cylinder has been cleaned up using a glaze busting tool, or in this case, a cheaper alternative - a foot of coarse sandpaper coiled round a hole saw that was 1/2" smaller than the cylinder diameter. this reveals thescratches better, and improves compression.

at the top inch of the stroke, the castelations reveal the rings and compression must have been in poor condition.

my own BVR cylinder was marginally better than this one, and runs like new! this is again due to the low technology, low compression, low octane design.

generally the water jacket gets blocked with rust and the only way to clear this properly is to have a set of Vire 6 core plugs (i supply) and rod out the pathway from the lower banjo to the front of the cylinder particularly prone to gumming shut. Exchange svc avail.

The cylinder is of a wear-resiting cast iron alloy (69.85mm bore, 70mm stroke)