I'm trying to check and set my timing, but I have a lumpy idle and the yellow mark for the leading is bouncing around (obviously). I have a street ported motor and I'm running an E6K.

I'm gonna check for vac leaks and such to try and smooth out my idle, but if I can't how will I know if the timing is good enough?

Is it even possible to get a solid idle @ 750 rpm with a street port?

Also, what is the easiest way to check for vac leaks. I seem to recall someone once telling me that if I sprayed break cleaner or something like that near a suspected vac leak that the engine would start to choke and that would be the indication that I had found it.

Ideas, comments....

-Kenji

 

https://www.rx7club.com/showthread.p...ht=base+timing

 

My streetport engine idles nicely at 750-800 rpm. But I don't run stock timing (5*ATDC), I run more like 10 degrees BTDC.

If your idle is lumpy, it is usually too rich. If it is hunting, revs going up and down, it is usually too lean.

 

Id say forget about the timing light. I was given some very gd advice by another member 6mth ago that i will share with you.
Use an exhaust temp gauge to tune your ignition timing. so long as air fuel is corect then advance or retard timing untill you see aprox 700deg cruise and 960deg max boost wide open throtle. these temps work for all set ups regardless of turbo size boost or port on pump gas. retard will make it hotter while advance will cool it.
Ive been tuning this was since with 20psi runs. people ask me all the time whats my ignition timing, i just shrug my sholders, who cares what you measure at idle so long as the timing at idle gives you the most stable sounding idle then your about rite..... whats important is the corect timing at max boost with wot,