Thermoquad on 340 (plug photos)
it looks like you have too much total on it, and maybe a bit too much initial.
sure the timing is at 22/34 which seems reasonable
Good ballpark start but now is time to get into further.
Measure the timing at various rpms from as slow rpm as you can get it, and write 'em down.
Then plot it out, or post and I will, 'cause I prefer graphs. :)
The reason is that 34* at 2000 rpm could be too much (especially if you will be using the vacuum advance), but 34* at 4000 rpm might be too little.
I get very good fuel/air #'s on the meter. Around 13.5 part throttle, 14 at cruise. WOT at 11-11.5 or so. So I should be rich enough for street driving, I'd think. But I am often told to go by the plugs, not the meter.
I think both are useful. The meter's disadvantage is just an interpretation based on the left over oxygen. If the combustion changes, the resulting products can be different than assumed in the O2 - AFR relationship. Mark Whitener has pointed out that changing the timing can often change the AFR shown on a meter, and that's obviously not an actual change in the fuel air mix. Bottom line, shoot for best performance and note the AFR changes as performance improves or decreases.
In general,the fuel mixture at
idle should be somewhat rich.
off idle should slightly leaner
and with increasing load go leaner and leaner
approaching maximum load (wide open throttle) get rich
