Anybody experience this problem with a CH745S. Starts fine. Idles fine. High speed - no load, engine surges violently. Engage blades, engine run fine. You can have blades engaged and reduce throttle to idle and engine wont stall. It will also accelerate cleanly from idle to high speed with blades engaged. No codes in memory (of course not). Gov adjustment has been verified and spring has been tried in different positions. When running, gov action/strength was compared to an identical unit. Seems the same. If the idle speed adjustment screw is turned in to various RPM's there is no surging. Overall condition of engine is good. 40psi on fuel rail. Has had fuel filter serviced regularly. Sometimes, I just hate advancements in technology.