Minn:

The Saito "Factory"black cylinders are anodized and polished before machining. If you pull a GK apart you'll see the inside is also black where the casting has not been cut. Since anodization changes the dimensions of the part, I've never tried any chemical blackening.

Going all the way back to Vincent motorcycles, I've been using a good quality "Stove" enamel and giving it a couple hours at 140F to set it. The baking is not necessary if you're careful, the first couple runs on the engine will take care of it.

The enamel requires careful thinning to get the coverage without getting thick, currently I'm trying fuel proof black spray paint. Much easier. Hobbsy's engine has the spray, the engine I'm doing now for a local fellow will get the spray also. We'll see how it works. Coating thickness is a lot easier to control with the spray too.

Bill.