Saving Old Seagulls

Thanks Peter and Todd.
Will try all of these things but will run with prop on first.

Chris.

Kia ora,
have just changed my needle to a 25:1 and am having
difficulties.
When I run the motor in a drum without prop at full revs petrol begins
running out of the fuel bowl indicator hole afterabout 40 seconds.! The
motor runs evenly with the needle flush with the top at half revs but oh
boy ...

Kia ora Phil and others who may be able to help,
I have just changed my needle so that I can run my 72,40 on 20:1.
Am having trouble tuning it in the tank and at present smoothest running is about 1and 1/2 turns above flush !
Is that likely to be the case?
Which is rich - screw down or screw up ...