Starter Clutch

[jhovel]

Sounds like your idle jet is blocked. Back firing often means lean mixture.
You can get the jets out without removing the carbies - using a small mirror.
You need to be able to see light through them. Yes, the hole is only fractions of a millimetre....
Carbies often overflow when the 40 year old rubber tip of the float valve needle dries out. Just give the side of the bowl s few whacks with a screw driver handle until it stops dripping. That's easier to monitor with the little overflow hose disconnected at the bowl.

Cheers,

Joe

[gm]

thank you Gurus
a few taps on the side of the offending carby with a plastic hammer, some fresh fuel and it started.  I used the idle adjuster turned it up let it run then lowered it and it idled perfectly.
thank you so much for your help.
gm