How to use a timing light??

[78Suburban]

I just borrowed a light and I will probably only have it for a day or two.. From what I understand, the red clamp will go to + on battery, the black will go to - on battery, and the inductive spark plug clamp will go on plug wire #1. How far down do I clamp it onto the wire, almost to the spark plug?

What vaccume lines do I plug (its a 78 K20, 350 motor, 400 trans) if any? and how do I plug them correctly?

so I attach all the wires then start the motor, or start the motor first?

thanks ,
James

 

[southernspeed]

Connect as you said. Plug the vac hose from the carb to the dizzy so the carb is blanked off...not the dizzy. Just push a small bolt or something in the hose.
Start the motor after checking everything is clear of moving parts. Shine the lamp on your timing mark that you cleaned earlier!!! Be really careful of the fan and alternater...they'll hurt your fingers lots!
Look for your timing mark and adjust the dizzy accordingly.

 

[MTMike]

Everything southernspeed said.

One thing to note is that on my '79 w/ a 350 I had to climb up and look down between the water pump & timing cover to see the marks with the light

Also, make sure you let the engine get up to operating temp before timing it so you get acurate results.

Mike