I have a 115 4-stroke, EFI. It stalls when going into reverse or from a medium or fast speed back to idle. It will stall but will always fire back up. Idle is showing 800 rpm on tach.

Sometimes at 1500 - 2200 rpm you can feel a a slight surge in power, almost like it's not getting enough fuel.

Anyone know what might be causing this?

I have replaced the plugs. Cleaned the fuel filter, and drained the gas tank to make sure no water was in it.

check the vst filter