Bullfrog Performance Products HOT COIL for the big block Honda GX240, GX270, GX340, GX390, Predator 420cc and many other clone big block engines. Bullfrog Performance Products HOT COIL features: Create the most powerful spark possible. Bullfrog Performance Products HOT COILS are engineered with a special built-in capacitor, exclusive only to our ignition coils. This revolutionary design allows energy from the ignition coil to accumulate in the capacitor until the voltage at the spark plug electrodes reaches the ionization point. At that split second the entire power of the stored spark is discharged at once, creating a spark 300 times more powerful. The result is faster, more complete combustion, and most importantly, MORE HORSEPOWER from your engine.