Rebuilt GM 4.3 setting base timing help

[drun_trucker]

1994 GM 4.3L V6
balance shaft
NON Vortec heads
Thunderbolt IV ICM

Crank, cam, and balance shaft timing marks all aligned on install. TDC has rotor pointing at #1 cylinder on compression.

***Initial Problems or Areas of Concern***
1. Air/Fuel screw in carb was damaged by previous owner and was replaced during the rebuild process. Not sure where to set it to get the best air/fuel mix while trying to time.

2. The rebuild block is from an automotive application. It seems that the timing cover and the marine harmonic balancer to jive. I had to bend the flange with the timing marks up, grove it out and bend it down to ride just above the pulley. I'm not sure at all the the timing marks are in the right location.

I know I'm missing information but I have been up down and around sideways trying to figure this out and my mind is a bit fried. If there is more that needs be known just ask or point me in the right direction. PLEASE

 

[Bt Doctur]

TB IV is point and shoot.
rotor should be pointing to #1 in the cap with #1 cylinder at TDC compression. you can verify TDC with a piston stop too; or make one. a old sparkplug base with the innerds broken out and threaded for a bolt.
install in #1 hole, rotate motor until it stops. mark harmonic balancer. rotate in the opposite direction untill it stops, mark balancer.
measure exactly half the distance between the marks, this is TDC and it should line up with the timing tab as " 0"

 

[Bondo]

1. Air/Fuel screw in carb was damaged by previous owner and was replaced during the rebuild process. Not sure where to set it to get the best air/fuel mix while trying to time.

Ayuh,.... Back it out a turn, 'n 1/2 to get it started, then tune it,...

 

[drun_trucker]

So 2 1/4 turns is too much? Is there an initial setting on the slow idle screw?

 

[Bondo]

So 2 1/4 turns is too much? Is there an initial setting on the slow idle screw?

Ayuh,.... It'll probably start at 2, 1/4,.....

Wherever it idles at 650/ 700 rpms,....

 

[drun_trucker]

But idle doesn't really matter if I can' t get it to run, correct? I mean once I get it running okay I can adjust the idle. And idle needs to be set in the water anyway with some exhaust back pressure. So I'd guess on the hose 850 would be close.

 

[NHGuy]

Just get it running, with water to the drive. Warm it up. and once it has enough heat start reducing the idle. Ultimately you want to turn down the mix screw til the motor stumbles then back it out til it gets smooth. Do the other screw too. You are trying for best idle at 725 rpm in neutral. It will drop to 675 in the water in gear once it's all set.