WilliamT

Thanks to all for your help.
I did have the notch to the front. It all seemed OK but I just wanted to be certain.

Must be something else causing the engine to surge and die when raised vertical, and also won't hold a slow idle without cutting out.
Is mounted inverted, after 12 months upright in another plane, so maybe I just haven't got the tuning correct for inverted?

Thanks again,
WilliamT