Hello, I have a 2011 Ariens 42'' Hydro-tractor which runs well for the first 10-15 minutes, then will occasionally stall out. If I apply the brake it usually will keep the motor running, sometimes I have to disengage the blades so it won't stall. Then once the engine starts running normally again (within a second or two) I can re-engage the blades and the mower runs fine again. I cut for about an hour tonight and this happened about 3 or 4 times. Any idea what could be causing this? I don't think this is an issue with the gas cap as it happens with both the cap on and off.