Hi Guys
I run an Irvine 46 in my low wing trainer which seems to have gone unreliable.
It's been great, starts easy and no dead sticks, but last Sunday at the field it started to play up.
I always hold the plane vertical to check engine is running right before I take off but this time the engine died after about five seconds, and I noticed a lot of air bubbles in the feed tube that I hadn't seen before?
I am sure that I have the needles set right, so I would appreciate some help.

Thanks
Don