Did I use my advance timing light wrong?

[WH23G3G]

I possibly may have messed up the way I checked my timing and could explain hard starting. I have an advance timing light with the knob on it you turn. Well I just left the knob at 0 and checked the marks on the damper and tab and aligned it with 10 BTC. I just decided to read the instructions with the timing light and it said to check initial timing by pushing the button while watching the timing marks and turn the knob until the line on the damper aligns with the 0 on the timing tab to get an initial timing reading. Then it said to turn the knob to the factory setting which on mine would be 7.5 BTC and then push the button while watching the marks. It then said to loosen distributor enough to turn so the damper line and the 0 mark on the timing tab line up. So I wasn't doing it like that. I just left the knob at 0 and turned the distributor until the mark is at 10.

[maxwellwedge]

The one I use is set to zero on the engine when you dial in the desired advance number on the gun.

[WH23G3G]

So that is the correct way to use it. The instructions seem pretty clear. You dial in the desired number, mine would be 7.5 BTC. Then I would aim at the damper and tab and shine the light and turn the distributor until the damper line lines up with the 0 mark on the tab. Is that the correct way to use this timing light?

[maxwellwedge]

Sounds like it - Try it and see how it starts and how it runs. Vacuum off and plugged while setting

[WH23G3G]

If I can even get it started. The carb is working how it should, nice streams of fuel out the nozzles but a hell of a time to get it started and I got a little flame, but nothing major like the last time. So I may have to have someone turn the distributor while I try to crank it. Should I have them turn it clockwise or counter-clockwise it's a 400.

[myk]

Yeah if you advance the timing too much it makes it harder to start; go the other way and it's supposed to be easier.  If you leave the knob at zero then you're just using the timing light without the advance/retard function, just like a standard timing light.  If you set the light either advanced or retarded then you just wait for the mark on the damper to match up with the zero.  It's been years since I timed my car with an advanced light, so someone correct us if we're wrong.

Edit:  not sure if it's counterwise or clockwise to advance and retard...

[Fred]

If I can even get it started. The carb is working how it should, nice streams of fuel out the nozzles but a hell of a time to get it started and I got a little flame, but nothing major like the last time. So I may have to have someone turn the distributor while I try to crank it. Should I have them turn it clockwise or counter-clockwise it's a 400.

To increase the timing you need to turn the distributor clockwise   ( and to decrease anti clockwise )

[WH23G3G]

So let me get this correct before I mess up my timing even more than it may be already. The instructions with this timing light are very limited, but when I'm not an expert on something I still always refer to instructions. I probably did read these instructions initially and just went by memory and that's why I did the procedure wrong last time I checked my initial timing. First on the instructions it says to point the gun at the timing tab and press the button and turn the advance knob until the damper mark matches with the 0 mark on the timing tab. This is your initial timing. Then the next step is to set your initial timing. It says to first turn the advance knob to the desired setting. Then it says press and hold the button while aiming the gun at the damper and tab. Turn the distributor until the marks line up with the 0 on the timing tab. My specs call for 7.5 degrees +/- 2.5 degrees which basically 10. Is that what I would turn the advance knob to and then turn the distributor to align the marks with 0? What do they mean by Advance? Is that the number of degrees before or after top dead center? I may have been doing it right all along except I didn't check my initial timing by turning the knob until the mark lines up with 0. I just left the knob at 0 and put the mark with the 10 BTC mark on the tab. Obviously you can tell I'm not an expert at timing but I think I should be able to figure it out with some answers. Maybe that's why it's hard to start and when it was running not very evenly.     

[Fred]

You can do it both ways.............(I just left the knob at 0 and turned the distributor until the mark is at 10.) or you can leave the knob at 10 and align the mark at the fly wheel at 0

[maxwellwedge]

To Advance (btdc) turn the distributor housing into the direction of the rotor rotation. To retard, turn the distributor in the same direction of the rotor rotation.  On Big Blocks the rotor turns counter-clockwise. On small blocks it turns clockwise.

I would turn it an inch or so counter clockwise and try it without the light. If it gets better - keep going.....if it gets worse go the other way a little at a time. Check it with the light after.