Timing Light Instructions, Which is easiest to use?

[WH23G3G]

I did a vacuum test at idle on that 76 Datsun B210 I'm trying to sell, and it wasn't too good. It was fluctuating between 10-12 INCH Hg, which is in between the markings that say (late valve timing, intake manifold leak or heat riser) and (late ignition timing) on the pressure tester. When the gas is pressed down it will sputter and when it drops back down to idle it will eventually choke itself out. Smoke is seen from the intake/exhaust manifold side and it's not oil because I've replaced the gasket and it's not leaking anymore and doesn't smell like burnt oil. I've also replaced the carb with a new one, the fuel filter and the EGR valve, and all vacuum hoses connected finalyl. It appears to have a fairly new fuel pump, and distributor and components. It starts right up with no hesitation at al, the float on the carb is right on the marking idling and when revved up. Compression was good, 120psi all the way across, the ignition coil is still good.  I'll need to know how to check timing anyway when I get my Charger going. Basically I can't use a timing light at all. I have tried and it doesn't work for me. No matter how many times I read the instructions for the timing light or the service manual for the car, it never comes easy to me. I've only got the basic inductive timing light. I mark the mark on the timing cover and on the crank pulley and hook the light up and turn on the car and even with the white paint marks it never looks aligned to me no matter if it was professionally done. I was wondering if I buy a digital readout Timing Light with a digital Tach readout, Is it pretty much a no brainer to set the timing to the factory numbers? The 76 Datsun I'm working on either has a leaking intake or the timing is off, so I want to rule out the timing first. It's factory timing specs. is 10 degress BTDC. With a digital timing light can I just loosen and turn the distributor until it reads 10 degress on the timing light digital readout and that's it? Hope someone here can help, I asked on the old message board, but thought it might be worth a shot on the new message board. Not one person at any of my local parts stores even knows how to hookup a timing light, so I haven't been able to find any help. The Nissan dealer won't even mess with a Datsun car this old.

[Chryco Psycho]

a didgit or an adjustable timing light will do that you can line up your marks at zero with the timing light set at 10* or what ever you need , the porblem is often the damper on the engine is not correct which is why I always time by ear instead   

[Ghoste]

How exactly do you do that Neil?

[Chryco Psycho]

turen up the idle screw or block the throttle up at 3000 rpm , advance the timing ... you will hear the rpm increase then for a couple of degrees it will make no difference then a couple more degrees & you will hear popping in the exhaust pipes , back the timing down to were it just starts to drop rpm again & return the idle to normal rpm

[Ghoste]

I'll try that.  How much advance should that be approximately?

[Chryco Psycho]

depends on the engine but usually 36-40

[Ghoste]

How often and how much do oe dampers move anyway?

[Chryco Psycho]

after 30 - 40 years the rubber drys out & deteriorates so it is common

[Ghoste]

Is there any way to visually verify this?

[Chryco Psycho]

use a piston stop in the plug hole & see if the piston stops an equal distance each side of TDC , Do not rotate the piston past TDC yopu could damage the piston

[Ghoste]

Thanks Neil.  No way to do it by inspecting the damper then, I am guessing.