Pop pop pop at idle

[GARRICK.CLARK]

Hi Guys. My Dell equipped motor pops out the exhaust at idle.
My thoughts are
lean mixture.
tight valve clearance.
Burnt valve/seat.
Air leak.
Have I missed any thing.
It only really starts as it gets warm.
Starting from cold its ok.
A leak down test will eliminate ??

[panel]

Lean at idle is my guess also.

[Leatherneck]

Any idea what the AFR is?

[SC3283]

dual dells? if so dont forget carb sync

[GARRICK.CLARK]

3 psi at idle.
I'll re check carb sync.
A trick I'm going to try is once its warmed up and doing its popping thing I'll spray some EASY START into each carb stack and see if the popping stops. I think its number 2

[Dan Dryden]

Probably a broken head to manifold gasket.

[GARRICK.CLARK]

AIr leak at 3 and 4 manifold.

[GARRICK.CLARK]

Hi guys.
I 've fixed the air leak.
On these dellorto's I have backed down the idle stops so as the butterflies don't open any of the progression holes.
I have 2mm holes in the butterfly plates to get the idle speed up. Question. Is it possible to adjust the plates like I have and get low flow to the mixture control needles.
I say this because even though I adjust them as per Air cooled.net's instructions I still get some little spits and pops.
Idle jets are 55's and they are not blocked, neither are the carbs.
My timing is locked at 24. don't no if this is part of the problem.
I have locked it so I can get an exact degree of timing when pinging starts.
thanks.