2011 CNS V2 Carb Bogging

ive been having the same issue tryin to "tune" this thing, runs like a wounded dog with the clip all the way up but my ngk b5hs comes out *white* move the c-clip down a couple notches and the plug looks good nice chocolate color but you can kiss the top end goodbye and say hello to the b~o~g...

nOT THREAD JACKING ! only for more info, maybe we can crack this CNS mystery
this is the thread i started a few days ago documenting my trial/ error
http://motorbicycling.com/f34/help-some-minor-tuning-issues-30465-new-post.html
 
treyoh5 said:
ive been having the same issue tryin to "tune" this thing, runs like a wounded dog with the clip all the way up but my ngk b5hs comes out *white* move the c-clip down a couple notches and the plug looks good nice chocolate color but you can kiss the top end goodbye and say hello to the b~o~g...

nOT THREAD JACKING ! only for more info, maybe we can crack this CNS mystery
this is the thread i started a few days ago documenting my trial/ error
HELP! some minor tuning issues - Page 3 - Motorized Bicycle: Engine Kit Forum
Click to expand...

The problem is not your needle, it's your main jet is too small. New main jets are hard to find, so you'll need to drill yours out. Mine ended up a #64 dill bit.
 
try running it without the air cleaner for a try. mine fell off one day when i was riding, but i didint know till i stopped. i was having the same problem. The "filter" element becomes saturated with oil and gas and can't aspirate properly. i noticed and immediate surge in power when it fell off ! i had done all that b.s too. now i just run it with no air cleaner. ifyou are worried bout rocks and what not, put some screen over it. also i have the same motor on a micargi prado deluxe. it pretty nice.
 
C.B. take a look at the filters from SBP, mine came un-oiled spray it with k/n oil and its a great filter. Fits cns and nt.
 
Bear with me as I am new to carburetors, but I do have experience with tuning EFI setups.

We've pretty much established that the Carb runs lean from the factory and it appears that the main jet size is too small.

Here is my situtation:

Choke off - Good idle, decent mid, WOT leans out under load and bogs.


Choke on - Will not idle, poor Mid, WOT = great
Seems like idle and mid are too rich, as I must petal for a while with load to clear out fuel from cylinder for it to run again.

Here is my question:
Do these observations seem on par with other people's observations of an out of the box- non-tinkered-with CNS?

Here is another question I have not seen addressed - how do access the main jet?
 
@hottscennesey. quit goofing and just use the choke lever that came with the carb. its right next to your left pickle (thumb). That is where i mounted it anyway. go back to the settings you had good perfomance at low and mid, and use the choke one click or half (you'll figure it out) for the WOT. Also, i use the choke to help slow down faster with the motor, instead or tearing up those stupid coater brakes faster than needed. i have never needed to "tune" the carb other than the idle. but that could have just been lucky draw. i live at sea level in south Texas. about 40~50 minutes from south padre. Harlingen to be precise. (air/fuel was all the way in when i got it) im on my second CNS cause the little nub broke that kept it tight. : ) Laters! p.s. i did have to mess with it a little but i covered it in the last post about the element being too wet. when it fell off and started breathing properly it was fantastic again.
 
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@greg58 XD it wasnt oiled naturaly. it got oily from the operation of the motor. ya know oil and gas like to move along surfaces unimpeaded. so it eventually became saturated. when it was new and dry it ran fine. but i will definately look at your suggestion. Thanks again.
 
circleball said:
@hottscennesey. quit goofing and just use the choke lever that came with the carb. its right next to your left pickle (thumb). That is where i mounted it anyway. go back to the settings you had good perfomance at low and mid, and use the choke one click or half (you'll figure it out) for the WOT. Also, i use the choke to help slow down faster with the motor, instead or tearing up those stupid coater brakes faster than needed. i have never needed to "tune" the carb other than the idle. but that could have just been lucky draw. i live at sea level in south Texas. about 40~50 minutes from south padre. Harlingen to be precise. (air/fuel was all the way in when i got it) im on my second CNS cause the little nub broke that kept it tight. : ) Laters! p.s. i did have to mess with it a little but i covered it in the last post about the element being too wet. when it fell off and started breathing properly it was fantastic again.
Click to expand...

This is very bad advise. You should never need to run your bike with the choke on, except when the motor is cold.

Your bike obviously isn't tuned very well if you have to open your enrichener to get it to take full throttle.
 
Hi, thought this info might be useful because i have the same carb

"For adjusting the carburetor for best performance, please follow the following setup: 1. Set the fuel/air adjusting screw all the way down. 2. Remove the metal plate that houses the slide and jet needle attached to the carburetor. 3. Set the jet needle valve C-clip to its highest setting (the setting that allows the jet needle to go in the furthest). 4. Turn the fuel/air adjusting screw 6-8th of a turn out. 5. Test the bike by riding it. 6. If the engine is bogging, fuel leaking from the carburetor, or any improper performance, stop the bike and turn out the adjusting screw another 6-8th of a turn. 7. Repeat steps 5 & 6. 8. If you screw the adjusting screw all the way out with no satisfactory result, set the C-clip on the jet needle to the second setting, set the adjusting screw all the way down and repeat steps 4-7 until you get desired results."

-found this on the bikeberry reviews of the carb
 
A cns2 carb can be hard to get tuned just right, biknut worked alot on the carb on a 66cc and I spent alot of time on a 48cc with same carb. " IF" you get it right it does run well.
 
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