I've got an issue with an OS 61fx that I'm hoping you guys can throw some suggestions at. The engine doesn't get run very often and sat for about 8 months with after-run oil (i think). Now, the engine will turn over with little to no issue and idle fine but will sputter and die when i get to 1/2 throttle. Should note that it's a new fuel tank and lines (H9 alpha 60). I've gotten it to go full throttle maybe twice out of about 15 times and it will last for about 10 seconds. Usually though, no matter how slowly I increase throttle, it starts to sputter at 1/2. I've set the high-end back to default (open about 2.5 turns) and tried to tweek to get it to let me go to full throttle but no luck. I've changed the glow plug, no luck. I HAVE NOT messed with the low-end needle. It seems to be getting fuel thru the line and there doesn't appear to be bubbles coming thru or excessive vibration. any ideas? I'm going to have another go at it this afternoon.

Thanks in advance
J