I use the Maguire's spray on rinse off bike cleaner on my engine and soap and water. I've got the grey engine on the standard, can I use this pig spit or S 100? Really wanna keep that grey clean, they look awful when dirty.
I have sprayed the S100 engine brighther on the entire engine, just made it look good. You can wipe the chrome on the fins if you want, but it really doesn't show up. Pig spit is great too.
Years ago, I went to a lot of car shows and remember being told not to use "Simple Green" on polished aluminum as it would corrode it. Don't know if it will or won't. I just remember the advice.