How to time the 12A's dual vacuum adavnace
10-24-17, 03:14 AM
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How to time the 12A's dual vacuum adavnace
Hello all, and thank you for taking the time to check in on this thread. After searching for a year or two about how to properly time a 12A with the stock Nikki carb and stock distributor, without finding a straightforward process/response that worked...I figured I'd start the thread myself!
Moving along, so I believe I understand the concept of how to time it.
Start with the leading wires:
a) Unplug the two vacuum lines feeding into the vacuum advance (VA) pots off the distributor; put screws/some kind of plug in the ends of those two hoses
b) While one person revs the engine to 4,000RPM, time the leading by unbolting the distributor and rotating it left or right using a timing light on the main pulley.
Then move on to the trailing wires:
c) Once the leading is timed, tighten the bolt for the distributor and proceed to unscrew the two screws on VA pot closest to the driver's side of the car and, at idle (I think...), adjust the trailing timing by either pushing it in towards the distributor or pulling it away from the distributor
d) Finally, after adjusting both, tighten everything down.
After timing, adjust carburetor idle speed screws if needed.
I believe this is all there is to it...however it has not worked for me and I am about to see if I happen to have a vacuum leak...if so, I will be buying hoses and replacing/deleting a whole bunch of stuff soon.
Thank you all again for taking the time to read this and, in advance (haha), thank you for the help! Have a great week!
- Brendon
Moving along, so I believe I understand the concept of how to time it.
Start with the leading wires:
a) Unplug the two vacuum lines feeding into the vacuum advance (VA) pots off the distributor; put screws/some kind of plug in the ends of those two hoses
b) While one person revs the engine to 4,000RPM, time the leading by unbolting the distributor and rotating it left or right using a timing light on the main pulley.
Then move on to the trailing wires:
c) Once the leading is timed, tighten the bolt for the distributor and proceed to unscrew the two screws on VA pot closest to the driver's side of the car and, at idle (I think...), adjust the trailing timing by either pushing it in towards the distributor or pulling it away from the distributor
d) Finally, after adjusting both, tighten everything down.
After timing, adjust carburetor idle speed screws if needed.
I believe this is all there is to it...however it has not worked for me and I am about to see if I happen to have a vacuum leak...if so, I will be buying hoses and replacing/deleting a whole bunch of stuff soon.
Thank you all again for taking the time to read this and, in advance (haha), thank you for the help! Have a great week!
- Brendon
10-24-17, 08:24 AM
#2
Waffles - hmmm good
iTrader: (1)
If you do it this way you will have to mark the pulley at full advance for the timing you need. The marks on the pulley are for doing the timing at idle. The way you have described will result in a very poorly timed engine. It will be retarded by a lot and probably not start or run well at all.
The factory method to time the engine is to not remove the vacuum lines, run it at idle (750 - 850 rpm) and put the timing light on the leading sparkplug wire and rotate dizzy to line up with the mark on the pulley. The trailing timing is done the same way to the second mark and is adjusted by sliding the trailing vacuum advanced pot on the dizzy in or out after loosening its mounting screws.
BTW, the FSM describes this in great detail. This site has the manuals online http://www.foxed.ca.
The factory method to time the engine is to not remove the vacuum lines, run it at idle (750 - 850 rpm) and put the timing light on the leading sparkplug wire and rotate dizzy to line up with the mark on the pulley. The trailing timing is done the same way to the second mark and is adjusted by sliding the trailing vacuum advanced pot on the dizzy in or out after loosening its mounting screws.
BTW, the FSM describes this in great detail. This site has the manuals online http://www.foxed.ca.
10-24-17, 01:32 PM
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If you do it this way you will have to mark the pulley at full advance for the timing you need. The marks on the pulley are for doing the timing at idle. The way you have described will result in a very poorly timed engine. It will be retarded by a lot and probably not start or run well at all.
The factory method to time the engine is to not remove the vacuum lines, run it at idle (750 - 850 rpm) and put the timing light on the leading sparkplug wire and rotate dizzy to line up with the mark on the pulley. The trailing timing is done the same way to the second mark and is adjusted by sliding the trailing vacuum advanced pot on the dizzy in or out after loosening its mounting screws.
BTW, the FSM describes this in great detail. This site has the manuals online Foxed.ca.
The factory method to time the engine is to not remove the vacuum lines, run it at idle (750 - 850 rpm) and put the timing light on the leading sparkplug wire and rotate dizzy to line up with the mark on the pulley. The trailing timing is done the same way to the second mark and is adjusted by sliding the trailing vacuum advanced pot on the dizzy in or out after loosening its mounting screws.
BTW, the FSM describes this in great detail. This site has the manuals online Foxed.ca.
And thank you so much for that link!!! I had no idea they had it on the website. I will give it a try this weekend! I will keep anyone else needing help with this updated, maybe even post a video on YouTube of doing it. I feel like some people have no idea how to adjust dual vacuum advance.
Thanks again!