Hello all!
Does anyone have experience of tuning FCR32/33 on NC23?
What camshafts did you use? Stock/HRC?
What was the jets size?

I am stuck in tuning FCR32 on my CB-1 with stock NC23 camshafts...

My FCR32 came from Yahoo and were used on a CB-1 (camshaft specification is unknown ) with these jets:
F.Main: #132
A.Main: #200
F.Slow: #48
A.Slow: #110

We made several dyno runs with steb-by-steb lowering main jet. At the moment my jet is #105 (which is stock size for CV carb for both CB-1 and NC23).
Even with #105 jet I have too rich mixture at the top of RPM (beginning from 12000).

Thanks in advance.

It would take me a month to write what this guy has already taken the time to put together,

http://www.factorypro.com/tech/tech_tun ... s,Pat.html

Read it all thoroughly and start from the beginning most dyno operators have never even seen a set of FCR's let alone worked on them follow the guide these guys know what their talking about
Si

sa.racing wrote: ↑

Thu Jul 26, 2018 9:31 pm

It would take me a month to write what this guy has already taken the time to put together,

http://www.factorypro.com/tech/tech_tun ... s,Pat.html

Read it all thoroughly and start from the beginning most dyno operators have never even seen a set of FCR's let alone worked on them follow the guide these guys know what their talking about
Si

Hi! Thank you for reply. Actually we tune it together with dyno operator :)

Thank you for this article - we have already read it (and print it and put it near Dyno before tuning) :)
We also have read this:
http://www.factorypro.com/tech_tuning_p ... gasEGA.htm
https://www.keihin-na.com/assets/1/7/slide_valve.pdf

Our problem is on the first step: choosing the main fuel jet on top RPM.
It's current size is #105 (started from #132) and still we have rich mixture on the top. I don't want to get lower, because this jet size will be less then stock CB-1/NC23.
So I am sure that I use wrong camshaft (stock camshaft from NC23).
I am waiting for GF Racing race camshaft to prove my theory :)

My current best result is 57 hp on the shaft with #116 main jet and still can't get to normal AFR on the top.

GF racing will be able to advise. But you can widen the Main air jet (MAJ) by one size to lean the mixture curve also. It works slightly differently to just the main jet. It will lean the mixture off more at the top end than the lower end of the revs.
Are you using an airbox?? You will find more hp, using a front ram feed airbox than stand alone pod filters (which can be restrictive).
Are your pod filters pulling in warm air from the heat of the engine? This will make it run rich also.