Just got the bike out of the basement last week after having it ripped apart down to the bearings over the winter...
I'm glad to say that she fired up great this year, I put her up on the (new) double leg kick stand and she fired up on the second kick! A quick turn of the the idle screw and she's all set, this year I can set the idle very low and she doesn't die out on me... (mainly due to improved throttle and clutch cabling I think)
I made quite a few changes to the bike this year, a few directly related to the CNS carb...
I have the CNS v2 carb with the red plastic air filter, so I changed the filter over to the low profile filter from Sickbikeparts.com (SBP-LPAF2, see picture). This filter fit the carb very nicely and only requires a slight bit more room in the frame than the red plastic filter. My frame is really tight but she fit. I didn't have to do any adjustments to the carb, she runs great, although I had opened up the red plastic filter a bit before I did my final tuning last season.
I changed the intake from the stubby cut/bent/welded unit that came with my Grubee kit over to the $3.00 cast short intake from gasbike.net. The cast intake is a bit bigger, putting the carb a slight bit higher and further back, but she still fit in the frame with the new air filter so all's good. You still need the spacer to mount the carb on this intake, but the seal fits nicely and it bolts up well. (I wish there was a cast intake available that fit the CNS without the spacer, but so far the only ones I can find are for the Super Rat top end with the wider lug spacing) I think the smoothness of flow inside the cast intake is an improvement over the rough ride the air takes over the welds inside the old intake.
I changed from standard flat mountain bike handlebars to taller BMX style bars, which required a complete re-cabling of the bike, in the process I made a few improvements... I added flexible lined noodles to both ends of the throttle cable and the carb end of the "choke" cable. Since my frame is very small the bend the cables take coming out of the top of the carb has always been an issue, the noodles really help a lot here, and the noodle on the throttle helps keep it stable when turning the handlebars. Last year the idle would vary when I turned the bars, so I had to keep the idle a bit on the high side or she would die, this year I set the idle very low and she holds stead no matter how I turn the bars.
I also removed the "choke" lever, since I never use the front derailleur any more I removed it and am using the three position shifter lever to pull the "choke". Its nice because it is integrated into the brake lever, so I was able to eliminate a cable and a lever from the bars. I have found I only need the "choke" for a few seconds when I first start to ride, and when I let off the throttle with the "choke" on she doesn't like to idle. I really like this setup because I can use my thumb to push the "choke" lever but not far enough for it to latch and lock on, this way the "choke" snaps back to off when I let go and she idles great, and it's always there for me to add a little more fuel when needed...
I also added noodles to both ends of the clutch cable, which helped me achieve a lower idle because the old stiff clutch cable was causing the clutch to bite a bit when I turned the bars, which would make the motor die if the idle was set low. So, 5 noodles later and I can finally rotate my bars with zero effect on the idle speed. I think I had these issues mainly because I have built on just about the smallest frame possible and everything is jammed in there really tight with sharp bends in the cables. That said, I recommend noodles for everyone!
