Can you detect a skip in it while it runs? (Answer this)
Keep looking for vacuum leaks
In the mean time, this is a simple test.
Hook up Mr. Timing light.
Unhook and plug the vacuum advance hose with a bolt/ pencil/ whatever.
Insure you are at the correct idle speed to time it.
Check your timing - adjust if necessary.
Keep the light on the marks
Slowly throttle up the carb (slow, to maybe 2000 RPM, just guess at it)
Is the timing mark moving further and further from correct timing?
'Nuther words, you should see the mark moving to compensate for increased engine speed (thus your spark gets thrown sooner and sooner)
If it ain't moving (it is still on your original timing) The Mechanical advance inside the distributor may be hung up OR most commonly the/ a spring that pulls the centrifugal weights back to return to center (when at lower RPMs) may have broken.
This is the results of this happening
1) The weights go outward all of the time
2) This immediately makes the timing back up (constantly, it is now way off)
3) Dumbfoundedly, you FINALLY check the timing
4) It is off a good bit
5) You change it to correct timing (the weights are still centrifugal-ed out- You don't realize it)
6) Timing is right!
7) There is no longer a mechanical advance, the faster you run the engine, the spark is not firing sooner as it should.
8) Lack of power/ just don't wanna pick up speed/ even backfiring may occur
Replace the distributor
Re-time it, as it was actually wrong with the spring being broken (and you moved it to compensate)
How'm I doin'?
Images (Click to enlarge)
Monday, August 29th, 2016 AT 3:32 PM