Motorcycle engine with an always spring biased open exhaust valve

An adjustable exhaust port 2-stroke motorcycle engine with an exhaust valve system comprising:

• a control rod mechanically coupled to a governor, so that said governor causes a rotation of said control rod;
• a center exhaust valve controllably linked to said control rod;
• a left exhaust valve controllably linked to said control rod and a right exhaust valve controllably linked to said control rod;
• a left control pulley with a profiled slot, said left control pulley mounted to said control rod and a right control pulley with a profiled slot, said right control pulley mounted to said control rod,
• wherein a rotation of said left control pulley controls a position of said left exhaust valve via a first pin sliding in said profiled slot of said left control pulley, and
• wherein a rotation of said right control pulley controls a position of said right exhaust valve via a second pin sliding in said profiled slot of said right control pulley;
• and
• wherein an initial rotation of said control rod causes said center exhaust valve to open first, and on further rotation of said control rod, and said profiled slot of said left control pulley and said profiled slot of said right control pulley causes said left exhaust valve and said right exhaust valve to open before said center exhaust valve is completely open in an overlap operation.

An adjustable exhaust port 2-stroke motorcycle engine comprising a:

• a control rod mechanically coupled to a governor, so that said governor causes a rotation of said control rod;
• an exhaust valve system comprising a center exhaust valve controllably linked to said control rod, and left exhaust valve and a right exhaust valve controllably linked to said control rod;
• and
• a left control pulley having a profiled slot, said left control pulley mounted to said control rod, and a right control pulley having a profiled slot, said right control pulley mounted to said control rod, wherein a rotation of said left exhaust valve and said right exhaust valve respectively via a first pin sliding in said profiled slot of said left control pulley and a second pin sliding in said profiled slot of said right control pulley of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system, and
• wherein said profiled slot of said left control pulley and said profiled slot of said right control pulley causes said left exhaust valve and said right exhaust valve of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system to open at different times with respect to each other, in a staggered operation, and
• wherein an initial rotation of said control rod causes said center exhaust valve to open first, and on a further rotation of said control rod, and said profiled slot of said left control pulley and said profiled slot of said right control pulley causes said left exhaust valve and said right exhaust valve to open before said center exhaust valve is completely open in an overlap operation.

A method of operation of exhaust valves of an adjustable exhaust port 2-stroke motorcycle engine comprising:

• providing a control rod mechanically coupled to a governor, so that said governor causes a rotation of said control rod, an exhaust valve system comprising a center exhaust valve controllably linked to said control rod, a left exhaust valve controllably linked to said control rod, and a right exhaust valve controllably linked to said control rod,
• wherein said rotation controls a position of said center exhaust valve, said left exhaust valve and said right exhaust valve;
• and
• operating said left exhaust valve and said right exhaust valve by opening at least one of said left exhaust valve and said right exhaust valve before said center exhaust valve is completely open in an overlap operation,
• wherein said step of operating further comprises operating said left exhaust valve and said right exhaust valve at a maximum rotation of said control rod, limited to less than a full open position of said left exhaust valve and said right exhaust valve in a limiter operation.

An adjustable exhaust port 2-stroke motorcycle engine comprising:

• a control rod mechanically coupled to a governor, so that said governor causes a rotation of said control rod;
• an exhaust valve system comprising:
• a first side and second side of a split center valve controllably linked to said control rod, or
• a left exhaust valve and a right exhaust valve controllably linked to said control rod;
• and
• a left control pulley having a profiled slot, said left control pulley mounted to said control rod, and a right control pulley having a profiled slot, said right control pulley mounted to said control rod, wherein a rotation of:
• said left control pulley and said right control pulley controls a position of said first side and said second side of said split center valve of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system, or
• said left exhaust valve and said right exhaust valve respectively via a first pin sliding in said profiled slot of said left control pulley and a second pin sliding in said profiled slot of said right control pulley of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system, and
• wherein said profiled slot of said left control pulley and said profiled slot of said right control pulley causes:
• said first side and said second side of said split center valve of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system to open at different times with respect to each other, in a staggered operation, or
• said left exhaust valve and said right exhaust valve of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system to open at different times with respect to each other, in a staggered operation, and
• wherein at a maximum rotation of said control rod,
• said profiled slot of said left control pulley and said profiled slot of said of said right control pulley limits an open position of said first side and said second side of said split center valve of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system in a limiter operation, or
• said profiled slot of said left control pulley and said profiled slot of said right control pulley limits an open position of said left exhaust valve and said right exhaust valve to less than a full open position of said adjustable exhaust port 2-stroke motorcycle engine with said exhaust valve system in a limiter operation.