Future Pilot cylinder modifications.Here is a cylinder off a snowmobile, notice the blue arrows where they added external boost ports right into the transfers. Here is a top view of the bottom of the cylinder, blue lines show the port. Side view Top view from intake side of cylinder. Same engine, same cylinder without the extra ports, the cylinder without the extra ports made 64-72 hp depending on what model sled you bought the engine with the external ports made 90 hp this engine also had dual spark plugs and dual ignitions. The port feeding the crankcase on the Pilot is way small, it would be nice to open it up like drawn in the picture below but the only problem is the casting is thin and weak in this area so anything other than just cleaning up the factory hole adds a large amount of risk to the casting cracking when you torque the cylinder down. How about welding aluminum blocks to the cylinder and installing longer studs to the cylinder is reinforced and so the hole can be opened up like in the picture below (that is a TRX250R cylinder pictured below) Or how about adding extra external ports like shown below, I drew it in 2 locations using 2 different colors because I am not sure where the best location to install them would be.