cant seem to tune the cns carb

How do you know its running rich? Be warned that if you accidently overlean it, you can easily fry the motor.

Also, try my new carb routing idea of just pluging the bottom overflow outlet insted of running it back into the intake.

Plugging the overflow may prove to be a problem, while it's vented separately so it won't vaporlock the bowl - if the float valve doesn't seat quite all the way (dirt/wear) & as most of us hafta mount the carby at a slight forward angle you could possibly flood the intake... given enough time and/or enough seep - you could possibly fill it enough to cause the dreaded hydrolock. Granted - it's unlikely, but that's why it's got an overflow drain *shrug* I jus' ran a line down to the crankset so if it's filled w/the urge to piddle - it can

Insofar as the OP's problem... it's really quite odd for a CNS to run unacceptably rich, have you done a plug chop? It may sound silly, but are you sure you're using the enrichment circuit (choke) correctly? I only ask as at first I had some confusion - but lever down (cable pulled tight) & the "choke" is on, up (slack) and it's off. Also, the fuel/air mix screw is for low speed/RPM adjustment - if yer actually runnin' way rich at speed you'll need to adj. needle clip position (up for lean, down for rich)... but I'd uncap all ports and see how it goes first.

Moons was absolutely right about lean = hazardous, defo wanna check plug color bfore & after messin' w/it... still a lil weird that it's runnin' "rich" tho



edit: Oh right lol, forgot to mention that the CNS hates a dirty and/or wet air filter (causes a crazy rich condition) so don't use the filter oil common on K&N style filters (the 2 cycle backblow is plenty 'nuff) - it really wants to be cleaned regularly & if it gets soaked in the rain or w/e it needs to be thoroughly dried. Not really a problem riding in the even heavy rain I've noticed - but sitting in the rain/washing your bike will do it in every time...