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Is the stock vacuum advance adjustable?

  • Thread starter Thread starter S-Car-Go
  • Start date Start date Apr 15, 2006

S-Car-Go

Member
Mar 25, 2003
332
0
16
San Jose, CA
Apr 15, 2006
#1
  • Apr 15, 2006
  • #1
I just installed in a Crane electronic ignition with a duraspark distributor. Set it up with light springs. Initial timing is 12 deg, initial + mechanical is 41 deg at 3,000 rpms. It fired up and runs great in the garage. Tried to drive it and it fell on it's face and backfired out the tailpipes. Disconnected the vacuum advance and it runs fine.

Can I adjust the factory vacuum advance? or do I need to buy an aftermarket ($30)?
 

thehueypilot

Active Member
Feb 25, 2004
1,084
0
37
Medina,Tennessee
Apr 15, 2006
#2
  • Apr 15, 2006
  • #2
Factory advance in not adjustable. Is your vac advance hooked up to a ported (timed) vacuum source?
 

S-Car-Go

Member
Mar 25, 2003
332
0
16
San Jose, CA
Apr 16, 2006
#3
  • Apr 16, 2006
  • #3
Yep, it's on the correct port. I guess Summit will get another $30 Thanks for the response.
 

dennis112

15 Year Member
May 15, 2005
1,561
36
79
Amish Wonderland of Central PA.
Apr 16, 2006
#4
  • Apr 16, 2006
  • #4
S-Car-Go said:
Yep, it's on the correct port. I guess Summit will get another $30 Thanks for the response.
Click to expand...

I've been down this route too with the duraspark. Research showed that it is a very common problem. The adjustable vacuum advance (which I have) does very little to solve the real problem of too much travel. What you will need to do is to fabricate a stop of some kind to limit the total amount of advance. This is the route that I have taken.

Until that time, just leave the vacuum advance of and drive the car. You probably won't know the difference, except maybe a mile or two less gas mileage.
 
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