[GreenMachine]

looks like u headed in right direction....good luck

[Rick O'Shea]

Ok, had to start somewhere. I dropped the main jet from 140 to 136 & left the pilot jet at 19 ( it's the leanest one I have). I'll run a tank at this setting and then drop to the 132, that's the leanest main I own, and check again. Then I'll start on the needle position. The higher the notch on the needle the leaner it gets ,right? High notch/lean-low notch/rich? Oh, by the way thanks for the help, Joe

[baird4444]

the smallest pilot jet I have is the 25...   maybe I should drop down myself.
" The higher the notch on the needle the leaner it gets ,right? High notch/lean-low notch/rich? Oh, by the way thanks for the help, Joe "
          coerectomundo!!   I've had mine in fer a couple of years and I still
    laugh every time I grab a handful in 3rd gear and it goes like stink...
   my mileage maybe could be better if I didn't twist it so hard but
   where is the fun in that?   - Mike

[Rick O'Shea]

Mike, which main jet are you running & what is your needle position? My bike has the classic exhaust, no catch can & a K&N pancake filter for mods. I am running non-ethanol 87 octane fuel although I get similar results on 93 octane, 42-45 MPG -Joe
P.S. Is anyone running a 30mm flatslide at a similar elevation, (2200'-3500') with similar mods? any input is appreciated.....

[baird4444]

Mike, which main jet are you running & what is your needle position? My bike has the classic exhaust, no catch can & a K&N pancake filter for mods. I am running non-ethanol 87 octane fuel although I get similar results on 93 octane, 42-45 MPG -Joe
P.S. Is anyone running a 30mm flatslide at a similar elevation, (2200'-3500') with similar mods? any input is appreciated.....

I've got the 125 main jet with the clip 1 ring above the center.
my elevation is about 660. I have the K&N filter with a drilled
thru  and opened up backend bazooka.
          - Mike

[Rick O'Shea]

Mike,are you sure about that 125 main? You don't mean 25 on the needle? My 30mm came with an assortment that only went down to 132, but it does have a 25 option on the needle. Tried the 136 jet today dropping from a 140,seems to run a little better at full throttle but I'm still getting 42 MPG. Guess I will drop to the 132 a start monkeying with the needle. Joe

[baird4444]

Mike,are you sure about that 125 main? You don't mean 25 on the needle? My 30mm came with an assortment that only went down to 132, but it does have a 25 option on the needle. Tried the 136 jet today dropping from a 140,seems to run a little better at full throttle but I'm still getting 42 MPG. Guess I will drop to the 132 a start monkeying with the needle. Joe

yea, mine came with the assortment from like a 140 to 132 main jets and a
38 and 25 slow or pilot jet. I bought my 125 at the local yamazuki shop.
    Have you figured out that you can pull the jet from the bottom thru the
drain cap hole? I used a mirror and I think it was an 1/8" drive 6mm socket
on a short extension...  heck of a lot easier and quicker.  I'd be glad to send you
all the files I've got on this if you want them.
                        - Mike

[Rick O'Shea]

Sure Mike, thanks! Any info will help. Down to the 132 main, the 19 needle jet and the leanest position on the needle. I'll update when this rain stops. Anyone have any preference of a K&N filter, cone style or pancake? Does the cone breathe better? Joe

[baird4444]

years ago when I was setting mine up I asked the same question.
  Kevin says that they both breath about the same. I can tell you that the
cone gives just a little more sucking noise on the intake but you get used
to it pretty quick.

[Rick O'Shea]

I was wrong about the pilot jet size. The CMW catalogue SAID it had a 19 installed but after I tore it down I found it was a 38!  WTF? Switched to the 25 & set the float to 19mm, the needle in the leanest slot and am waiting on a 120 main jet. Thanks to all of you, and Mike Baird especially, I think I have my carb sorted. Joe

[GreenMachine]

just proves u can't assume anything....

[Rick O'Shea]

Good point GM, I'll remember that

[Rick O'Shea]

First chance I've had to try out the new jets and needle position with all this rain and working daylight to dark. Started fine and ran normally with the enricher for warm up. Shut the enricher down and it only would idle with the mixture screw turned all the way in (or bottomed out) Pulled out of the drive and it ran for 100 feet, it then backfired out the pipe and died. Too tired to adjust any further but I will tonight. 120 main, 25 pilot, needle in leanest or top position and float set at 19mm. Any suggestions? Joe

[baird4444]

sounds lean if you had the screw all the way in....
I'd raise the needle to the top and see if that gives the desired effect.
              - Mike

[ace.cafe]

You might have gone a little too lean in your attempt.

I think if the Keihin and Mikuni jet numbers are similar, you can probably try a step richer pilot jet, like a 27.5 next.
I think maybe a 120 main is too lean. Try at least a 125 main.
And I usually try to richen the needle one notch at a time until the midrange seems good.
That allows you to see some progressive results, and you can gauge how it's doing as you go along.

Do some plug chops at various throttle openings when you are getting close to where it feels good. Make sure it's not too lean.