2 Stroke 15hp suddenly sounds like 4 stroke and low power

[MichaelAngelo1]

Left the ramp without issue. Moved spots a few times. Motor suddenly difficult to start and idling very low sputtering out. Gave it some gas and noticed the motor sounded different - low pitch as a 4 stroke would! Also very low power.

Does this sound familiar to anyone? Any tips where to start?

Will do the routine spark plugs swap, checking spark. Compression is 80 both cylinders as it always was.

 

[racerone]

Running on just 1 cylinder I would say.----You have installed a new water pump impeller every 3 or 4 years I hope.