I know my engine is a 250CC but what is the HP of my 1150 polar force?

The formula given earlier (power in HP = torque in ft-lb X RPM / 5252) is correct, and using the "Power Curve" I too found a peak horsepower of almost exactly 7 HP at 3600 RPM. The power level is fairly close to 7 HP from 3000 RPM to 3600 RPM. At 3060 RPM, which is the speed where the rated torque (11.5 ft-lb) is specified, the power output is 6.7 HP and at 3400 RPM, the output power is 7.0 HP, only 0.1 HP less than the 7.1 HP at 3600 RPM where the engine is turning faster but producing less torque.

A horsepower rating without an associated speed at least asserts that an engine can produce a certain amount of power at some speed. A torque rating without an associated speed guarantees nothing about output power. I have applied hundreds of ft-lbs of torque when loosening frozen bolts but was producing almost no horsepower because the bolt turned very slowly.