Exhaust popping centres only

[KwakaRascal]

Hi all,
just reconditioned engine and overhauled carbs new manifolds new plugs leads cap coils condensers the full monty.
The centre exhausts only are randomly popping independently of each other on tick over. It’s fair to say the popping is not frequent but occasional.
Air screws initially set at 1 1/4.
Main jet needle set to 3rd notch.
Any ideas welcomed.

[kev edwards]

You could have a leak at the exhaust gaskets causing the pop.

[zapo]

Cylinders 2 and 3 run off the same set of points so worth rechecking points gap......assuming that you are not on electronic ignition of course.

[KwakaRascal]

Hi Kev Edwards,
Thanks for the advice I’ve released the exhaust clamps and repositioned the Half shells and bolted back up.
Unfortunately got no petrol to test out.
What’s going on?

[KwakaRascal]

Hi Zapo,
Again thanks for your advice, your right the coils are shared and have carried out all the checks that you mentioned.
There is one other thing that I’m unsure about.
When checking the ignition timing using my multi meter set on circuit continuity ( Buzz tone) so one connection to earth & the other attached to the points spring, upon the points starting to part at “ F” timing mark, there’s no sound from the meter when you would expect one.
On the other hand if I detach the low tension lead from the coils and then repeat the timing process the meter sounds off as expected.
My question, is this correct? or an indication that I’m missing something?

[KwakaRascal]

Popping exhaust now resolved.
Air fuel mixture adjusted via Colour Tune.
Now running sweet as a nut.
Thanks goes out to Warren3200gt who helped with this.
Happy days ahead, once it stops raining.

[warren3200gt]