CNS carb working great....

Nightcruiser
1 thing I didn't notice in your article, look right next to idle screw, do you
see that brass cap? take it out and there is an air/fuel adjustment
screw, just read your article quickly so you may have mentioned it
and I would guess that the problems most people have is that they don't
realize the cns carb is like one off a car with both idle and air/fuel adjustment
hope this helps


nightcruiser said:
Thanks for your compliments Bill. I had written this post a while ago and had expected more response since there were so many posts about problems with the CNS carbs. It's surprising the thread has been so slow, I hope at least some people were able to get some helpful info from it.

I am no mechanic, or expert on these motors (yet), I am still learning about them as I experience this and that. I do, however, have the drive and curiosity to work and figure this stuff out, and a background in engineering doesn't hurt either! Although my major was electrical engineering, mechanical engineering was also a big part of the curriculum. I have always had a great curiosity to know how things work, be it mechanical or electrical, and now with computers. These little motors have given me something to dissect, something mechanical to experiment with that is cheap and FUN.

Did I mention FUN? Riding these bikes is just a gas! Almost every face I see has a smile plastered on it (not quite as big as mine!), except sometimes the faces of parents of young boys who know the next words out of his mouth is gonna be "I WANT ONE!" LOL
Click to expand...
 
BarelyAWake said:
Never had the slightest issue w/my CNS V1 & I've been usin' it for a coupla years now;

Click to expand...

Thats because this bike is just "BAD AZZ !!! "
I love that old school chain guard.
What size male adaptor did you use for that copper line off the carb? I'm guessing the tubing is ¼" was it a ¼" feral Male adaptor?
 
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Desert Rat said:
Nightcruiser
1 thing I didn't notice in your article, look right next to idle screw, do you
see that brass cap? take it out and there is an air/fuel adjustment
screw, just read your article quickly so you may have mentioned it
and I would guess that the problems most people have is that they don't
realize the cns carb is like one off a car with both idle and air/fuel adjustment
hope this helps
Click to expand...

Yah, I didn't mention the cap over the mix screw in my write-up because the version of the CNS carb that has the cap didn't exist yet when I wrote it. But that's a good note to add to this thread, thanks...
 
OK cool.. I found the pic in your bucket that shows a close up & it looks to be the same as pressure switch line on a water pump of compressor I still have to figure out what size will fit the stock carb thread to ¼" Male adaptor
 
Jumpa said:
OK cool.. I found the pic in your bucket that shows a close up & it looks to be the same as pressure switch line on a water pump of compressor I still have to figure out what size will fit the stock carb thread to ¼" Male adaptor
Click to expand...

I'm not quite sure what pic you are referring to, guessing it wasn't posted by me, and I don't really understand what you are saying about the pressure line switch...
 
I Was talking to "BarelyAWake " about his copper fuel line ! I thought I clicked "Quote" on his message but guess I didn't.
My fault for the confusion sorry M8
 
My CNS works great too. I'm going to be buying another as I broke mine, but I have a feeling that it will work great once I drill out the air idle mixture cap. I adjusted mine on my current broke carb and the bike responds MUCH better at low rpm. Almost whip snap throttle response.
 
Yeah,


My carb's needle only had one slot for the "e" clip to go so I had to repurpose a bobby pin to be a spacer so that I could make a customized setting. I noticed a huge difference in how the engine runs now. No more bogging down in the mid speed range. My bike now goes too fast.
 
The 2012 carbs only have 1 needle position. I'm lucky as I am replacing a 2010-11 carb with the bottom end of a 2012. So I can keep my carb lid and needle. :D
 
Is the barrel what I should see when I twist my throttle?
I think my throttle is wide open, so it wont idle properly.
And Where it holds the valve pin up should be bent down?
Because when give it gas it floods heavy through the waist line.
 
IndependentRider said:
Is the barrel what I should see when I twist my throttle?
I think my throttle is wide open, so it wont idle properly.
And Where it holds the valve pin up should be bent down?
Because when give it gas it floods heavy through the waist line.
Click to expand...

With the air cleaner assembly removed from your carb, the part inside that moves up and down when you twist your throttle is the slide, or barrel as some may call it, because it is a cylinder shape, in this form of carb.

IF, your throttle IS wide open, you would probably not see anything but the very bottom of the slide, and the engine would be very difficult to start, and would not idle, at all. It would scream like a banshee untill it quit.

...where it holds the valve pin up...
This is a very precise adjustment, and may need to be done more than once, or twice, even when following perfect instructions!

If it floods gasoline out the overflow of the carb, there could be a number of problems with the float needle valve, or the float itself.
It could be adjustment, it could be grit from the tank obstructing the valve seat.

An inline fuel filter is very important on these little carbs.

Good luck, buddy... I know it's difficult to be independent, but some things are best learned when taught, hands on, by a friendly, competent mechanic.
rc
 
Okay, I adjust the valve pin, where it held at broke, but I found a way to keep it holding on. I gave it gas and it actually worked better.
How should I get the slide to excel up and down?
 
IndependentRider said:
Okay, I adjust the valve pin, where it held at broke, but I found a way to keep it holding on. I gave it gas and it actually worked better.
..Excellent! Now get a filter!

How should I get the slide to excel up and down?
Click to expand...
'excel' doesn't quite translate, for me...

Movement of the slide is accomplished by the throttle cable, pulling upwards, (open), against spring pressure, which resides withing the slide barrel, and acts against the top bonnet of the carb.
Lower position is controlled by an idle speed screw adjustment on the side of the carb body.
Upper capability is caused by physically against the carb body, or cable length.
The carb slide holds the needle for the metering jet.
Needle position is adjustable, as is the actual main jet it interacts with.

There is a small clip device which hold the ferrule end of the throttle cable and needle within the slide, by the return spring pressure, and also another spring steel holdong device that sits within the top of the slide body.

The ferrule on the end of the throttle cable must fit down through a hole within the slide, then slip back up into a recess, to be retained by the keeper.
... all the while working against the spring, which must be over the cable, between the slide and the top bonnet before assembly to the carb body.

Is that clear as mud?
:-)
rc
 
haha, yeah, I believe so.
But I guess I was trying to say is how do I get the slide from being stuck, it works when I take it out but tight when I put it in the cns carb.
 
IndependentRider said:
haha, yeah, I believe so.
But I guess I was trying to say is how do I get the slide from being stuck, it works when I take it out but tight when I put it in the cns carb.
Click to expand...

There is a groove along one side of the slide.
It must be indexed with a corresponding nub inside the casting of the carb.

This keeps the venturi cut out aligned, and also the ramp machined in the bottom of the slide that corresponds with the idle speed adjustment screw.

Perhaps the cast nub had been damaged?

Good luck
rc
 
I don't know. someone else told me what you said. and It still gets stuck..
I can see scuff marks every time I put it in and out..
I've tried what you guys said... still don't understand why its doing that..
 
IndependentRider said:
I don't know. someone else told me what you said. and It still gets stuck..
I can see scuff marks every time I put it in and out..
I've tried what you guys said... still don't understand why its doing that..
Click to expand...

Well sure you do!
Find out what is causing those scuff marks and polish them.
:-)
rc
 
The edges are rubbing on them.
I hammered the slide in worked only to pull the slide up.
But it gets stuck. hey where it gets stuck its more narrow.
Can I smooth it out?
 
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