Its not the gas... when i start it it only goes to 900 rpm drops below 450 rpm almost stalls, sometimes it does then goes upto 650 the falls back to 450 almosts stalls again then upto 550 and kindof stays there a few days ago it normally went between 1.5-2k rpms when i started it and dropped to around 650-700 i think. could it be a leaking hose?