Originally Posted by everycredit
I don't think any detergent is going to work. Aircraft stripper may work (this is to repaint/refinish cylinder head covers). A wire brush may pit magnesium/magnesium alloy. I''m not too experienced working with magnesium, so I don't know how soft it is and what you can get away with.
Paint with high-temp primer and paint.
Super Clean is not a detergent.
Aircraft paint strippers are hazardous and require a respirator as do the aircraft paints. Unless you are experienced and have the equipment, stay away from them.
If you want to restore the factory look and durability, have the OHV covers powder coated.