Trouble with CNS Carburetor. Need help!

[sunsetboy]

CNS carb choke and tube

I pulled the choke completely because I don't need it here in sunny CA and the tube points downward from the bottom port but I am getting a lot of discharge on my bike and it's getting quite messy. I'll post a pic tomorrow. I've run this now for 3 months and lost the filter on the first week. Dang urban streets!

 

[JTinFL]

I,ve been using the CNS carb for a month on a 48cc.The pink tube was crimping and causing an intermittant power loss.Replaced with a piece of 1/8 ID clear plastic tubing from hardware store.I do see fuel going from bottom to top whith engine running.Someone said that it was a float problem if any fuel came from bottom at all.Yes i still have the top and bottom connected together.I put a piece of plastic tubing on each of the other 2 ports coming out of top and routed them down the seat post down to the rear where kickstand is mounted.Just to keep junk out of carb if nothing else.After getting air/fuel mixture scew adjusted then idle screw.The bike runs like a champ.Has great low end,can take off with no peddling and when you open it up it gets a low throaty sound and cranks up to 30 mph.This carb has been a mystery since it came out and I only know what's working on this bike.Yours may be differant setup.

 

[sunsetboy]

Thanks for the idea. I'm doing an overhaul of my motor anyway so it's about time to go through the carb. I'm still working on the fine tuning bit of the carb because I may be experiencing sn exhaust leak but I'll find out more when I tear the carb apart.

 

[motorpsycho]

The problem is that you have the pink hose still attached to it you need to remove it from the top of the carb and let it hang from the bottom They come from china like that for some reason disconnect and you will be on your way!!!

yep, that tube is a vent /overflow.
with it connected at both ends, it is building a vacuum in the carb.
It needs to be vented to keep the fuel moving. just like a vented gas cap, the fuel needs to "breathe".
if it can't breathe, a vacuum will develop and the fuel will not want to flow like it should.
think of pouring a liquid out of a can that only has one small hole in the top. it gurgles and doesn't want to come out very well. pop a second hole in the lid of the can and the liquid will flow out of the first hole much faster.

 

[motorpsycho]

Thanks for the idea. I'm doing an overhaul of my motor anyway so it's about time to go through the carb. I'm still working on the fine tuning bit of the carb because I may be experiencing sn exhaust leak but I'll find out more when I tear the carb apart.

what does an exhaust leak have to do with the carb.?

 

[motorpsycho]

Ok I will thanks! And what is the deal with that little choke lever? When and how should I use that?

you're kidding about that right?
move the choke lever to "on" for starting in cold /cool weather.
move the choke lever to "off", when starting in warm/ hot weather.
the choke partially blocks the air intake side of the carb, when it is in the "on" position so the engine gets more fuel than air at start up, which makes for much easier starting in cold /cool weather.
if you try to run the motor with the choke on, it either won't run, or it will run very badly.

 

[Top Cheese]

yep, that tube is a vent /overflow.
with it connected at both ends, it is building a vacuum in the carb.
It needs to be vented to keep the fuel moving. just like a vented gas cap, the fuel needs to "breathe".
if it can't breathe, a vacuum will develop and the fuel will not want to flow like it should.
think of pouring a liquid out of a can that only has one small hole in the top. it gurgles and doesn't want to come out very well. pop a second hole in the lid of the can and the liquid will flow out of the first hole much faster.

It's hanging. And a bunch of gas is coming out the end of the tube.. What now?

 

[motorpsycho]

It's hanging. And a bunch of gas is coming out the end of the tube.. What now?

tap the side of the float bowl with a plastic handle screw driver.
the float may be stuck.
if that doesn't work, you may have to take the float bowl off and re-adjust your float level.
no gas should be coming out of that tube at all.
gas coming out means that either your float is stuck down which is letting the needle and seat stay open when the float bowl is full, or your float level is adjusted so that the float never rises enough to close the needle & seat.
OR...you have a bad float and it is getting gas in it, which will make it too heavy.

 

[sunsetboy]

Thanks motorpsycho! I tapped it real good and something happened because my carb works as advertised. I also needed a new intake gasket because the last one burned up.