Hopefully this will find it's way to the right people.
Motor Specs are below.
Carb is Eddy 1405 with stock jets, needles and orange springs.
I have purchased an ASPX D2 Air/Fuel Ratio Gauge (Not the most expensive and not the cheapest, reviews are good and I have a friend with it and it's accuracy is pretty good when compared to his OEM system) and an Eddy 1479 Tuning Kit.
My engine currently runs rich judging by the plugs and the exhaust.
On to the questions:
1. How do I know which step up springs I need?
I read the instructions and it doesn't seem to cover that. Only 'Trial and Error'
It is kind of a trial and error thing, but spring changes only take a couple of minutes.
Your elevation will make a difference between your engine and someone else's on here.
(The higher elevation, the lighter the springs needed.)
I would try the pink springs first (If it leans way out right as you get into the throttle off idle, then they are to light)
What made it easier for me was to block the secondaries from opening and go out and open it up to see what those primary jets do. (as far as AFR)
Change jets as needed to get the WOT about where you want it (Probably the 13 or so range)
Then unblock the secondaries and use the AFR reading to get your WOT in the range you want with all four barrels running (again probably about 13 to one)
Then you can start changing needles and springs to bring the low and midrange throttle AFR into range.
Here's a scenario you don't want to overlook.
If your WOT is good as it is, but the low and mid range throttle AFR is rich you can use a larger needle and possibly lighter springs instead of a jet change. (a larger needle does the same thing as a smaller jet, except for wide open throttle. (the jets themselves handle WOT)
Another thing to keep in mind is that even though they say 14.7 to one is a chemically perfect A/F ratio, does not mean the engines like it.
Usually at that lean of an AFR the engine will run so lean it runs crappy, and even can get hot from running too lean.
I have mine set at about 13.5 to one right now all through the throttle range and it's right on the edge of lean missing, but when it's hot out it runs great.
2. If I take the readings from the AFR, How do I know how much to adjust?
The tuning guide shows adjustments in 4% increments.
From my understanding two jet sizes = about 1.0 number on the AFR (so if it reads 11.5 now then two smaller sizes on the jets would make it 12.5)
I will be installing the AFR in the morning and then starting this tuning process and I am trying to gather as much info as possible before I start.
Thanks for the time.
:prayer:
