Never had a problem on the powder coat case and between the fins. Good info though!

 

I think I would use a nice soft paint brush.

 

You can use a pressure washer if you are smart about it!

 

Nothing smart about using a pressure washer, and it's not even necessary.

 

Walmart, or any sporting goods store, sells a gun clean brush originally designed for the M-16/AR-15. Here's an amazon link: http://a.co/fF3xMtb . It works great for those tight spots.

I start off by spraying down (with a regular garden hose nozzle) the COLD engine. I then spray a small area at a time with either Bleche-Wite or Hot Rims Wheel & Tire Cleaner. Both are great at de-greasing and both have been safe on my paint, bare metal, and chrome. After letting the spray soak for a 30 seconds, I scrub it, then rinse. I found the Meguiars does just as good as the Black Magic, without the nasty smell.

 

I use carb or brake clean give it a good shot then rinse with water, get oil stains out of raw aluminum pretty good