Hello

I've got a ys-63 wich runs great but there is something that I'm not completly satified with. When the engine spends some time in idle and I hit full throttle it takes about 5-7 seconds to reach full power. I rarely take it to idle during flight since the airplane that I have it in needs speed (I probably land at 1/4 throttle) also when it reaches full power it will go as high as 11700 and then go down to 10900. The engine won't quit or sputter it only takes too long to accelarate. Can someone tell me if it's the low end needle or the regulator or what? I'm flying with powermaster saito/ys 20/20 and a 13 X 6 APC. Everything else this engine runs great and has lots of power.