40 Plus dies when choke turned off

[Arbian]

I replaced the needle on a 1973 40 plus at end of last year to run on 25:1 before sticking in shed for the winter. I had only started / run very briefly before that on the 10:1 as I had just bought it so can't really say how it was running on that. Anyway it will start with choke and full throttle without too much effort but does not like it when choke turned off and runs briefly (and erratic throttle response)then dies. Any thoughts?

P.S. Water flow good and no signs of leaks at head gasket.

[Stelios_Rjk]

The screw that push down the needle in the slide. Did you screw it all the way down? This screw should be screwed up to the point that creates a level with the slide (and I hope that was English language and not Chinese ).

Or maybe the carb needs a good cleaning. It is leaking fuel when pushing down the button?

[Arbian]

Yes I turned the screw down to the flush with the top of the carb barrel. Fuel is coming out the carb bowl hole when primed.

[Keith.P]

Main Jet restricted, probably from old dried out 10:1 fuel.

[Arbian]

Thanks Keith, Sorry for delay in response been on hols. How do I clean this out?

[Keith.P]

The easiest way is to remove the float bowl, using a strand or more of copper wire so not to damage the jet, clean out any residue of old fuel.

[Arbian]

Cheers, I will give that a go.