backfire/carbs/valves???

[GotaT]

Alright guys, so I have gotten the car running! Its the 71 911t. The problem I am having is a backfiring problem. So, Ive got a carb sync tool and adjusted the carbs best i could, the car idled much better and overall sounded better, but still backfired, so i then adjusted the valves - fairly difficult to fit the feeler gauge in there, but now it is done. I can now hear a very minimal valve clatter, I dont think its anything really to worry about for now.

So, the backfire.. at idle it will backfire every once in a while and I can see that when it does the #4 Weber carb has some blow back. The car smells as though it is running too rich (hence the backfire im sure).
ANY IDEAS???

Oh, most of the time it will back fire at lower rpms. If I lay into it it pulls with no backfire but seems to be lacking some power and if cruising at a steady speed every now and then you can feel a little resistance as if the car wasnt getting enough fuel, or possibly loading up.

ANY Ideas?
Thanks
Mitch
mas2868@yahoo.com

[alex jelepis]

I'm having the same issue; mainly @ idle and upon deccelaration; could be an exhaust leak/problem as well.

I bought my car from an estate sale last June, so I still need to correct the carbs as it sat for a few years. Much work ahead still this Spring before I hit the road.

Any advice on carb adjustments would be great; mine are the original Zenith 40's and I'm still running the Marelli dist - 106K original miles. Idle is rough and the backfiring seems to be mainly in the right carb bank.

Thanks!

Alex