Mercury - Power Tune Internal Engine Cleaner Quicksilver Series Spray Formula 858080Q03. Overview. Engines have a way of telling you when they are not at their best. Maybe the throttle feels a little sluggish, or the idle develops a faint stumble that wasn't there last season. It's subtle, but anyone who spends time on the water can feel it. That is where Quicksilver Power Tune Internal Engine Cleaner earns its keep. It freshens up the inside of your engine, clearing out the layer of carbon and