Guys,
After a long panic ridden winter, I finally got the engine back in the car. Thanks to Chris Streit from Moto Delta for helping me beyond all reasonable expectations.
So the engine now sports some domed pistons to get higher compression (Mahle P&Cs score on ebay) and has gone through a 20 minute break in; running rough but not bad @ 2000 RPM.
Now it comes time for weber tuning
I have this document on tuning the webers I got from someone on the board that goes something like this:
Idle adjust to the linkage +1/4 turn.
Idle mix, two full turns out from the seat
Air mix, 1/8 turn out from the seat
The car won't idle like this (not surprising), so I turn in the idle screws about a full turn each side to get it idling ~1200.
Then "The procedure" says to turn in an idle mixture screw until the engine 'slows down' and then back out 1/4 turn.
NONE OF THE IDLE MIX SCREWS SEEM TO DO ANYTHING
Meanwhile the carbs are popping like crazy, a couple of cylinders in particular.
So I back the idle mix screws out to the two-turn mark and begin messing with the air-correction circuit. WOW; what a difference; the engine starts to increase in revs, so I continue to back it out until the increase in RPMs stop, and leave it there. Repeat this procedure with the other air correction screws and get the same results.
Now, re-adjust engine idle with the idle screws to ~1000 RPM.
THing sounds much better (very little popping from the carbs, occasional backfire from the exhaust which may be a leak down there).
Still, the idle mixture screws have NO effect; I can screw them in ALL THE WAY and the car idles fine. WTF?
So, I take it for a ride around the block and notice right away that when coming off the throttle, it takes the motor a long time to come back to idle; like 4 seconds or so. Before the engine rebuild the throttle response was fantastic; very quick both on and off throttle. Something is obvious amiss.
Any ideas?