i've never had a problem with simple green and discoloration, but i never soak the parts, i just spay and scrub with a toothbrush, and then rinse with water. i'm thinking now that a good rinse is probably a very good idea, otherwise discoloration or spotting could occur even without soaking.
> I'd echo Lee and Chuck: be extremely careful with Simple Green--
\r?\n> you use it don't answer the phone or get distracted because damage
\r?\n> occur-- in a while it is no longer just microscopic either, but
\r?\n> notice with the unaided eye results just like Chuck describes. I
\r?\n> had poor surface results from Blue Lightning Parts Wash/Carb Cleaner,
\r?\n> another water soluble and biodegradable product.
\r?\n> I would not hesitate to recommend many of the items from Griot's
\r?\n> Garage, as I think their products do as they describe and quite well,
\r?\n> Ken Wehrenberg, Hermann, MO