The copperhead (Agkistrodon contortrix) is a member of the pit viper family, like most of the venomous snakes in North America. The copperhead (Agkistrodon contortrix) is a member of the pit viper family, like most of the venomous snakes in North America.
The Command Thrust models use the same bigger gearcase housing as the Mercury 150 FourStroke, but with an all-new 2.38:1 ratio ideally suited for pontoons and heavier boats. Itâs the first true oversized gearcase in the industry for outboards in this horsepower range.
Now when we increase the spark advance (the point when the ignition spark occurs, at the sparkplug, before-top-dead-center of the compression stroke [BTDC]) we get more power BUT we also get more heat. There is a point after which we get lots more heat and very little extra power.