Mercury - SpitFire 4-Blade Aluminum Propeller 14" Diameter x 14" Pitch Right-Hand Rotation 4 Blades Aluminum Polished Finish 8M0084493. Overview. There's something about the feel of a boat that leaps forward the instant you hit the throttle - steady, confident, and full of pull. That's what you get with the Mercury SpitFire 4-Blade Aluminum Propeller (Part Number 8M0084493). It's not just another four-blade prop; it's one that surprises you with speed that rivals a three-blade, while holding the