Originally Posted by 64nailhead
Curious as to why you changed only 3 plugs?
If you put in heavier springs, then the centrifugal advance will come in later, which is not what your after. As cdminter said, your want all of the advance in by 3000.
In terms of the timing, IMO, I'd change the remaining plugs and clean off the 3 you already changed, then unhook the vacuum advance and plug the line. Set the total timing between 34 & 36 and find out exactly what rpm it is all in by, and then drive a WOT throttle session and recheck the plugs immediately and see what they look like.
It will not hurt the motor to run it with no vacuum advance. And, oh yes, MAKE sure your balancer is marked accurately for #1 TDC.
I didn't see where you checked you vacuum, where is it at idle? Did you check for leaks?
i didn't change any spark plug but just 3 caps of the wires because on of them was cracked by the heat and the others were going to, i put heavier spring because advance was all in just over 2000 RPM, today i will try to disconnect the vacuum advance and see what happens.
As i said before the mark on the balancer wasn't matching the tab on the timing cover so i fixed the damper by machining a new groove in the right position, i didn't degree the cam, i thought was an overkill for a mild motor like mine but now i realize it's a smart thing, i will for sure next time.
I can take off valve cover and check the TDC.
By measuring the voltage coming out from the O2 sensor shouldn't be lean , 800 to 850 MV should be the ball park and mine is going from 800 to 900 MV with peaks of 1000, picture of the spark plug doesn't make justice to me.