I have a 2008 Street Bob that I am doing a build on. The bike is pretty well stripped down now and the cylinders are as accessible as they are going to get. They are painted black w/ the edges machines so that the silver aluminum shows. What is the best way to clean the cylinders? Is there a clear paint that can be sprayed on so that the stay clean longer, or will all the clear paint just burn off?

 

Rust-Oleum makes clear 2000 degree heat resistant paint. I never used it, just know it’s available.

 

It's just a cleaner, but HD's engine brightener works very well for keeping the black parts black and the aluminum shiny. Stays on after a few washings too.

 

Best to try some sort of biodegradable cleaner like "Top Gun" made by Gunk. Spray it on room temperature, let it soak on the surface for a minute, rinse away with cold water. Repeat.
Will likely take several applications but it doesn't hurt the aluminum (non Caustic) like a lot of the stronger caustic or citrus cleaners which will dull your machined fins. After you get them all clean, spray on that Harley engine detailer. Kind of like armor all for the black paint.

 

I believe citrus based natural cleaner is what parts washers use. Once you clean them I think you need to have soak them in oil to prevent any rust forming. Berrymans Chem dip loosened up all the carbon on my pistons