Recently I posted a message asking for ideas on what could be causing the drop in power at full throttle once the engine started going past 4000 rpm. I installed a gauge to measure fuel system pressures. All reading were taken on a cold engine, 70 F ambient temperature. Control Pressure = 2 bar Primary Pressure = 4.9 bar Rest Pressure = 2.9 bar Rest Pressure after 10 minutes = 2.5 bar Looking at my chart, it looks like primary pressure is at the bottom end of the allowable checking pressure 4.9 to 5.5 bar. I can set the primary pressure to the setting range of 5.1 to 5.3 bar. My question is; Will raising the primary pressure affect the Control Pressure? Is there a way to adjust the Control Pressure? How is it done? Maintenance History Major tune-up performed just before Nashville trip. New coil last week. New fuel filter 3 weeks ago. Fuel pump suction strainer is clean. Fuel suction pipe is rigid and has no leaks. Air Filter is clean. No signs of vacuum leaks. All lines connected correctly. So, what do you guy's think? Scott Mueller 002981 RNDOLA [Non-text portions of this message have been removed]