I am cleaning up the carb prior to fitting to a 602 AK. In the fuel bowl, there is the main jet, and another jet?? thing. It is screwed into a boss about 1cm from the bottom of the bowl, has an aluminium plug in the top, a floating ball in the bottom. When I dismantled it, it had a perished O ring as a seal. What sort of seal should it have, and what does it do?

In the Haynes manual, It doesnt show up - however page 56 shows the Solex 32 and this jet just above the main jet (item 9)

Bob

Bob,
if you look more closely at that cross section in Haynes, you should see the dotted lines (indicating a drilling) leading across to the accelerator pump.
From there, there's another drilling leading up to the accelerator pump injector nozzle via another ball valve.
Both of those ball valves must be functioning correctly in order for the accelerator pump to work.
I've found that as long as both ball bearings are free to move, that's about all that's needed, although that's assuming that the diaphragm isn't split and the injector nozzle isn't blocked...

Sam, thanks for that link. Page 44 shows item 'H' Ball Seat and it looks like there is a 'O' ring under the head of the valve (not jet as I erroneously called it.)

Thanks also to Ken for the explanation of the function of the valve.

Just another query, in the carb refurbish kit were two hard plastic collars about 1cm diameter. Where are these used, as I don't see them on my carb.

Bob,
those were in the last refurb kit which I bought for a single choke carburettor, which was a good while back.
IIRC, they may have been seals for the ends of the spindle, although they either were not needed on that particular carb, or I never fitted them...

ken