The finished edges of the cooling fins on my black engine are getting what looks like spots on the machined surface. I was wondering without paying alot of money, what other people have used to polish the edges of theircooling fins? I don't want to screw up my black powder coat with some polish that won't come off the black if I get any on them. I'm thinking great winter project. Let me what you've used if anyone has done or is doing this.

 

You might try some very fine wet sanding. Something like 2000, 2500, or 3000 grit paper. I have done this on a prior ride with good results. On the other ride after wet sanding I used some never-dull polish to finish it off. I think never-dull will leave a residue on your powder coat, but you might be able to remove it with some simple cleaners and a brush. I would test it first on an out of the way area to make sure you can remove the residue. Good luck.

 

Try S100 Polishing soap. Be sure the cylinders are cool and bike in shaded area. This stuff works with water and after polishing just rinse it off. Works great!

 

You can use a 320 grit to greatly speed up the project,then go to the finer paper after that.As far as keeping the polish off the black cannot help you.The fine sand paper may be your only option.It will stay looking good for a long time without polish.

 

Aren't they diamond cut edges? seems sandpaper would mess things up...

 

Had the problem on my 07 twin cam! Tried sand paper,never dull, mothers alum polish! Nothing worked. Bought a cordless dremel 2 speed and #4 polishing compound(white)stick. With the small polishing wheel I finally got it off. The fins look like new again. Takes some time but well worth the results!

 

A scotch brite pad and a small block of wood works wonders and is simple and clean, once a year keeps them looking like new.

 

I had the same thing and I just washed my bike with s100 and they look 100 percent better.

 

They're not diamond cut but they do have a kind of scalloped edge. I wouldn't take sandpaper or anything that abrasive to them unless I was prepared to take them all the way down to flush.