I have a 2006 Suzuki DF140 with a strange problem. It will run well at 2000RPMs, but as soon as I kick it up to 2600RPMs, it appears to be starving for fuel, as it drops back down to 1500. Without touching the throttle, it will go back to 2600RPMs for a few seconds and go back down. I have used fresh gas with Sea Foam, tapping from a 5gal tank, changed engine fuel filter, checked fuel line with primer bulb and even tried pumping the bulb when problem occurred. Not sure where to go from here. Is there another filter in the engine? Any ideas out there?