cns carb adjustment?

bluenosegoat

bluenosegoat

New Member
I recently put a cns carb on my mountain bikes 68.5cc engine with a sbp pipe and shift kit. I got the carb from spooky tooth and there are no instructions with it so I am a little confused as to what the adjustment screws do. I seem to be running rich but before I go messing with I would like to know what the adjustment screws adjust! The forward one (towards engine) I assume is higher rpm mixture while the rear screw is for idle? Anyone know for sure?
 
I can't tune up this carb too.
Anyone can explain how to adjust this two screws? I know one is air other is rpm..
 
the cns carb settings are as follows , and i have found to be the best setup

the bottom tube is overflow for have a tube on it running downward
the 2 tubes side by side , plug the left one and run a tube on the right one as a vent
the top one on the other side with the barbs on it run a tube on it as a vent

for the idle screws ,
left screw is your air/gas mixture (in is less air)
right screw is your idle speed (in is speeding it up.

hope this helps :)
 
I cant get my ideal to stay put, if I have it to low it dies, so I put it up some then when I run it the ideal goes up by itself. If I stop to ajust it it lowers by itself, and if I leave it ifeal by itself it gues lower and lower till it dies, anybody know whats up with it, I made sure I didnt have any air leakes, but it seems like it, or does anybody knowdnut
 
float may not be set at the right level draining the bowl then when you blip the throttle it gets filled again how dose it ride ? any flart spots in the rev range?
 
I had a similar problem with idle and it just turned out that my throttle cable was sticking a little bit every now and again! A little teflon on there and problem gone. I hope its that simple for you.
 
It could of been the float, cause the engine leans forward making the carb lean at 30to 40 degree angel. Any way I was runing it around 25 mph, then it diedl wated awhile started it again then it died again, had to ride it back home with no engine pull. I took it off, and put my stock carb on it:-||
 
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