Thermoquad on 340 (plug photos)

[yellow rose]

Yes, thought I was adding a lot with the .149 secondaries on top of the .101 primaries, and that the .038 nozzles would be too much for sure, but it just took it all with absolutely no sign of being too rich so far. I have done a number of drives and WOT runs, and it's just now looking good.

Now that you are getting your fuel ring down there it's easy to watch the fuel ring get thinner and thicker by removing or adding fuel.

A .060-.080 wide fuel ring is a good starting point to tune from.


Glad you have this working. Hard to beat a well tuned TQ.

 

[midnight340]

Rumblefish360, your comment about keeping a log book for anyone diving into learning more about carbs (or timing/plugs etc.) is good! I would never have gotten to this point without being able to refer back to notes!!

I wanted to know this stuff when I was 14, but it wasn’t until I got past some “sex, drugs, rock n roll” and some work years that I could finally focus enough to figure it out.

 

[rumblefish360]

LMAO, singing to the choir! You and me both.
My work years are ending. Down to a single digit and a half. Then it’s nothing but play time.

 

[Demonracer]

I've kept a log book as far back as I can remember. I put everything in it, tire pressure, weather conditions, jet size, track temp, & anything else I could think of. It has come in handy for tuning at different tracks.

 

[midnight340]

I hope everyone is doing OK in these strange times.

So I keep playing a bit to zero in on my A/F #’s, the right timing curve, plug heat range, and fuel ring at base of the porcelain. And am pretty confident I’m there.
But I do have a question. All is good all round, idle, cruise (at most any speed) stays right at 14:1 A/F. Pulls good wide open, mostly 11’s on the meter but plugs don’t look too rich. BUT on a hill or mid throttle I see 16-17 A/F. Is this OK or too lean?