SB Needles to Resolve Lean WOT with SUs

[Duffman]

What are you asking for the set of SM needles?

Oops, sorry, couldn't see price on cell phone, can see it on my laptop!

Edited July 9, 2019 by duffman

[240260280]

You can push the stock N47 deeper into the piston to enrich the whole range:

 

[AK260]

Forgive my ignorance - I have to ask to learn: how does pushing the needles up differ from dropping the jets? With my limited knowledge, I would have said that it’s changing the annulus area akin to winding down the jets, but is there something special going on when you move needles instead of jets?

[240260280]

The ring annulus change is the same whether you drop jet or raise needle. The location of the annulus from the carb throat where the venturi pulls fuel through it, and from the top of the fuel differs.  It will probably be the same effect as you point out. 

[240260280]

Altering the fuel level is another parameter for tuning a/f ratio.

[Craig24]

I am new and learning how to decipher the postings. When someone says SU, most of the time they mean SU-H (roundtops) Not SU-HIF (flattops) with Integrated Float, also the flattops have a "Anti-stall fuel rich mechanism" that keeps this from being a problem.

Edited July 11, 2019 by Craig24

[siteunseen]

Yes, you are correct sir.

[moritz55]

Bump on this thread....   

Wanted to let you all know I have extra sets of "SB" (2 sets) and "SM" (1 set) needles.   They were too rich for my L24 config so am selling at a good price for anyone who uses them.  

I am currently using "SL" Needles with very good results... as it's close to the N-27 stock needles.

Many thanks......