Figuring out my carb problem(s)

CNS carb, which I am just about to place gently on a large rock before hitting it with a sledgehammer.

The plunger should...move, right? As in, it should slide up and down inside the carb? In mine (which used to run badly but no longer will at all) the plunger is so tight that it nearly takes an act of a deity to get it out.

Any suggestions before I just buy another carb? I've had nothing but problems with this one. For what it's worth, it's a CNS66 carb on a 49cc motor, which I know others have complained about.

I finally got it pulled apart and saw what problem I caused...I had the plunger turned around so the slot (where the cable feeds through was at the set screw instead of the angled bit at the bottom of the plunger, where the set screw would adjust the plunger height.

The set screw went into the slot, and widened it enough that it locked the piston into place. I guess it's back to a NT carb for me anyway, as I also had throttle problems right from the start.

Is your carb level with the ground? Perhaps it's leaning too far back.

patricklogsdon said:

I've got a similar problem with my CNS carb on a 66/80 cc GT5 engine kit that I just installed/bought. My problem though is that the bowl just starts flooding with gas and it won't stop. I took the bowl off and examine the float...(everything seemed OK)...I took off the air filter, and twisted the throttle, saw the motion of the thing going up and down inside...I DON'T KNOW!!!...GRRR..anyone else haviing gas just pour out the overflow tube??. please reply to this forum and: [email protected]. THANKS!!

Click to expand...

So....like night and day!

I bought an NT carb from Bluegrass and it was amazing how much better this is. The CNS V2 carb (with the "66" serial number sticker) clearly was much of my problem right from the start. One I put it on and connected it up (with a different twist throttle, but using the same throttle cable) it started with one pedal push and runs very nicely.

The adjustment screw on the NT carb appears to do absolutely nothing, but it's running...*shrug*. Next up is the 60T sprocket and some new brake pads, and I think I'll give it a shot riding to work. It's been a long haul to get this running properly....I've had it about 1.5 years and have only run it about 10 kilometres.