I bought a CNS carburetor and initially I had quite a few problems. Recently though, I rejetted the jet a few sizes smaller to a 70. I was confused when it seemed to bog down when I went up hills like it was really lean considering that it appeared to be really rich until 1/2 throttle.
I then read this thread and tried switching out the CNS needle for the NT stock carb needle. Now power is great and the A/F ratio is almost spot on until 1/2 throttle before bogging down. I plan to move the c-clip up one to lean it out a little more and then drill out the jet one size larger. If my theory is correct, this will give me great performance throughout the entire range.
It appears that the CNS carb stock needle is just too thin. It lets in way too much gas from closed to half throttle. The result is that even when the jet is too small your mixture is too rich part of the time. It looks like the fix is a thicker needle that lets in less gas at the right time. Then just rejet the main jet like normal so that you are getting a good amount of gas at full throttle. Finally, tweak the c-clip a bit and then tune the carb with the A/F screw on the outside.
My CNS carburetor does not appear to leak at all.
Hopefully this will help solve many people's problems with the CNS carburetor. I have not found a way to get the throttle cable length corrected yet.
I then read this thread and tried switching out the CNS needle for the NT stock carb needle. Now power is great and the A/F ratio is almost spot on until 1/2 throttle before bogging down. I plan to move the c-clip up one to lean it out a little more and then drill out the jet one size larger. If my theory is correct, this will give me great performance throughout the entire range.
It appears that the CNS carb stock needle is just too thin. It lets in way too much gas from closed to half throttle. The result is that even when the jet is too small your mixture is too rich part of the time. It looks like the fix is a thicker needle that lets in less gas at the right time. Then just rejet the main jet like normal so that you are getting a good amount of gas at full throttle. Finally, tweak the c-clip a bit and then tune the carb with the A/F screw on the outside.
My CNS carburetor does not appear to leak at all.
Hopefully this will help solve many people's problems with the CNS carburetor. I have not found a way to get the throttle cable length corrected yet.