Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

7045281 RICH IDLE / LEAN WOT

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77cruiser:
Is the idle mixture set to highest idle RPM/vac?

Mikecaterina:
Yes, idle mixtures set to highest reading/smoothest idle then adjusted lean (clockwise) 1/4 turn just as vacuum signal wants to start moving lower

Cliff Ruggles:
If you can acheive smooth idle then turn the mixture screws in and slow the engine you are able to lean it out so it's not stinking because it's too rich.  When I set the idle mixture screws I'll turn each one in until I just hear the engine start to slow down then back them up about 1/4  turn or so till it smooths out.  Or basically the best idle quality at the leanest settings.  Turning them in from that point to lean it up will stink worse than having a little more fuel to it.

You may find that the overlap from that much camshaft on a small CID engine is most of the problem.  No mention of how much timing you have at idle but it's also a player in idle quality and stinky exhaust.....

Mikecaterina:
Hi Cliff, 18 deg @ idle

Went for another drive can see light puff of black smoke at tail pipe when idling. Not bad but noticeable to me.
Yes camshaft is probably a tad too big and not enough compression I think may be a problem.

If I cover carb with hand at idle, engine will pretty much stall, if I pull vac line off idle spikes up around 1000rpm

Same as if I do a tip in test at 2000rpm, covering drops rpm dramatically and pulling vac hose increases rpm.

Had another good look at nozzles whilst running, looked dry. After I shut down nozzles look wet but nothing on blades is this normal?

Thanks

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