I had the webers on before the rebuild and they ran great so I don't believe the ignition is not up to snuff.It is just fine tuning,they are not running terrible or anything just not perfect the way they were before.The only real changes to the motor are the euro pistons and the cams,hence the change in jetting.

To add to the confusion. I just had my 2.8 built by Ralph Meaney, well know to the NW guys. He dyno the engine in the car, and this is what he set it up with. No gurgles, flat spots, NO issues.
AC - 160
Main - 150
Venturi - 36mm
Idle - 60
Emul. - F7

The dyno shows it goes a little lean from 5800 to 6500. I am going to step it up to 155 mains.

It dyno's at rear wheels, max, 229 HP @ 7,000 rpm. Max torque 196 @ 5800 rpm.

5800 rpm is 218 HP

PMO got back to me and suggested starting with 145 mains and 180 airs or stay with my 135 mains and go to 170 airs.I will try the 145 mains to start with and go from there.

I have the exact engine with different carbs. These carbs are stupid in a way. There is only 3 simple circuits. What you do with each circuit is dialing in.

my engine pulls pretty good from 4k-5.5k in 5th gear with 135 mains & 190 air correctors. Can't say above 5.5k for any distance.

at 3.8-4k rpm is where I see the mains taking over EGTs. My EGT's when fully on the mains is great.

hot plugs is not to substitute for a rich mix. It's step 1. Forget about acceleration. Pick different rpms and gears and hold steady looking for lean pops. If not it's rich. I currently use NGK BPR8ES and plugs stay clean. It's easier to clean hot plugs occasionally that a colder plug 5x as much while you're finding out how lean you can go on the idle A/F mix. I read Sherwood's post about the A/F mix screws responding to very small adjustments. He's right and I can prove it with EGT temps.

all above crap is a prejudicial rant

The idle is now good,around 950rpm,a tiny flat spot from 2000-3000 and then at 3500 seems to come onto the cam.The only spitting and popping I have is below 2000 in a higher gear than I should be and light cruising around 2900 or so.Just the slighest push on the gas pedal eliminates all popping so it really is more when on the decel or under no load cruise.I have turned the mixture screws out 1/8 turn on all barrels and will try that.It is pouring rain right now so I may be chasing my tail with the drastic change in atmospheric pressure.I don't have the 145 mains to try out yet so that will have to wait.

the 2000-3000 flat spot is when accelerating?

"popping around 2900" is with a full 10 mile warmed up engine with very clean spark plugs at a steady throttle?

Does the popping sound like a group of cylinders going lean or just a single pop every few seconds? If it's a single pop every few seconds it's probably a single or 2 cylinders going lean, not necessarily all cylinders. What I did on that single pop every few seconds is track down which cylinder was going lean by turning only one cylinder out 1/2 turn. If it didn't stop that pop I returned that 1/2 turn rich to the all equal turns baseline and try another cylinder, etc till I found which was the culprit. Once I found the lean cylinder I reduced the 1/2 turn rich to 1/4 rich and looked for it to pop or not. Etc.

My #4 cylinder is the only one richer than all the other equal turns. Once I completed that exercise I changed the hot NGK BPR5ES to new BPR7ES and reduced my new baseline turns another 1/8 turn. At that point I had another lean pop occasionally. At that point I went to a colder BPR8ES. The colder plug eliminated the pop. My BPR8ES runs clean.

Generally going from one NGK heat range to the next is about 100 degrees F change in tip temperature.

above may not be exactly what happened to me but it's a good explain.

After the idle mixes were set I went after the acceleration circuit.

Combustion heat is power. I sought as much heat as possible with nice looking spark plugs.

Brent

Here is how I have mine setup.


34mm venturies
60 Idle jets
145 Main
180 Air Corrector
F3 Tubes
BP6ES Plugs

You can read more here:
http://forums.pelicanparts.com/porsche-911-technical-forum/348641-weber-idle-jet-question-you-weber-experts-2.html

Left this morning with no popping at all even cold.There still is a very flat spot from 2-3k's,probably just a different feel from my old ciis pistons and cams.I will leave this setup until motor totally broken in and then will try to dial it in perfectly.

I tuned my accelerator pump flows by adjusting flow lean till it fell flat when driving then slightly adjusted more flow till the flat spot was gone.

If acceleration flow is rich you cool the EGTs noticeably and it'll bog, wait a second and then zoom away.. Better is max power high EGTs so it's an even max acceleration.

again.. just my routine