Inside the 2010 Grubee Skyhawk CNS Carb

GoldenMotor.com

Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
I ordered it from Spooky Tuesday and got it on Thursday evening. know Im a big quitter for not staying with the CNS, but I feel like I adjusted everything I was able to adjust.

So far the carb seems to stay on great, no issues. I had a ever so slight got yesterday, drop my C-clip down a notch and the thing runs great now. I think I can tell a definite torque difference between the 49cc and the 66cc. The 66c has a little more bottom end.
hhmm, i'll have to check my mail again and see, did you call them or order it from their website? i did it through the website (and sent them a message today asking where it is (but i think they're closed right now))

as for the torque, from what i've heard, the 66cc is a stroked version of the 49cc
 

biknut

Well-Known Member
Sep 28, 2010
6,653
475
83
Dallas
hhmm, i'll have to check my mail again and see, did you call them or order it from their website? i did it through the website (and sent them a message today asking where it is (but i think they're closed right now))

as for the torque, from what i've heard, the 66cc is a stroked version of the 49cc
I thought it was bigger bore.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
I ordered it from Spooky Tuesday and got it on Thursday evening. know Im a big quitter for not staying with the CNS, but I feel like I adjusted everything I was able to adjust.
Well, I received the carb rebuild kit and put in the kits different jet and needle and it fired up, road with the throttle full for a bit, I dropped to idle and it died and wouldn't start without choke and now has bogging again.

Cory, by the video pic it is still a CNS carb, or does the NT have the same top (choke and throttle cable)?

Found spookys carb, it says it's for a 66cc, this is a 48cc motor.
I wonder if that has been prob all along?
The carb says c-32CND66-EPA on it.
 
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Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
Well, I received the carb rebuild kit and put in the kits different jet and needle and it fired up, road with the throttle full for a bit, I dropped to idle and it died and wouldn't start without choke and now has bogging again.

Cory, by the video pic it is still a CNS carb, or does the NT have the same top (choke and throttle cable)?

Found spookys carb, it says it's for a 66cc, this is a 48cc motor.
I wonder if that has been prob all along?
The carb says c-32CND66-EPA on it.
i just threw the carb on, didn't swap any of the parts over and it runs really good.

it only has one cable coming out, the choke is a little lever on the side of the airfilter.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Ya, I have an NT speed carb here missing the throttle cable, plunger and needle but I just ordered a new NT, I don't have time to dink around with a completed new customer bike like this. I'll mess with the CNS on my own time and bike.

It stinks a 'new and improved' motor kit don't run.
 

AzToker

New Member
Feb 28, 2010
78
1
0
Too Stoned, Az
Hey i just wanted to share what i was going thru as you guys were having the kinda same problem. I did get mine running better now, I found out i had no upper head gasket and my muffler was somewhat clogged even tho it new. I couldnt feel full pressure coming out of it as i had the trike running at the same time doing both hands to see which blows harder ( ok that didnt sound right) and the trike was blowing way more than the colson was. Put a straight pipe on and it runs soo much better. So i think i solved my problem. So hoping that might be the problem. So take some time out of ur busy day and pull ur upper head off to see if there a gasket, if not use the one came with the kit and maybe put a different muffler on it while u at it and test it out!!!
 

Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
Hey i just wanted to share what i was going thru as you guys were having the kinda same problem. I did get mine running better now, I found out i had no upper head gasket and my muffler was somewhat clogged even tho it new. I couldnt feel full pressure coming out of it as i had the trike running at the same time doing both hands to see which blows harder ( ok that didnt sound right) and the trike was blowing way more than the colson was. Put a straight pipe on and it runs soo much better. So i think i solved my problem. So hoping that might be the problem. So take some time out of ur busy day and pull ur upper head off to see if there a gasket, if not use the one came with the kit and maybe put a different muffler on it while u at it and test it out!!!
i'm running mine without the cap, but thinking i may want to cut it open, take out all the muffler-ness in it, weld it back up. although i may be better off doing a more custom setup.

for right now, capless works just fine. loud, but not obnoxious.
 

TEM

New Member
Jun 28, 2009
8
0
0
Va
Hi I bought a CNS carburator and put it on my grubee skyhawk 48cc engine. It works great except it floods out the overflow tube and it will not idle. I havent played around with the idle screw yet but i will see if it can idle. Anyway i was thinking that the reason that it is flooding out the overflow tube is that the carb is at and angle and is not level, therfore it is flooding out of the bowl because it is tilted. If this is the case then how do I fix this, do i get a manafold that is bent to make the carb level?? and i am still kinda confused about the idle screw and the idle air/fuel screw. Which screw does what? I have a pretty good idea that the idle screw ajusts the idle but what is the idle air/fuel screw?
 

Skarrd

Member
Oct 13, 2010
501
2
18
34
Chandler, AZ
Hi I bought a CNS carburator and put it on my grubee skyhawk 48cc engine. It works great except it floods out the overflow tube and it will not idle. I havent played around with the idle screw yet but i will see if it can idle. Anyway i was thinking that the reason that it is flooding out the overflow tube is that the carb is at and angle and is not level, therfore it is flooding out of the bowl because it is tilted. If this is the case then how do I fix this, do i get a manafold that is bent to make the carb level?? and i am still kinda confused about the idle screw and the idle air/fuel screw. Which screw does what? I have a pretty good idea that the idle screw ajusts the idle but what is the idle air/fuel screw?
the one next to the filter is the idle air screw, and the one in the middle is the actual idle screw (it nudges up the throttle, cracking it open so there's enough airflow for it to idle)
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
The carb should be mounted as level as possible. The fuel will seek it's own level inside the angled carburetor and the carburetor is designed for that level to be even in relation to the float bowl gasket surface.
 

Shlink

New Member
Oct 3, 2010
23
0
0
USA
I'm having this exact same bogging issue. I didn't find this thread in time so I made my own.
Some people have suggested it could be an air leak. I'm not very knowledgeable about small engines/carburetor adjustments, But I DO think the way this carb mounts/seals is extremely prone to air leaks. In another thread I posted several pictures and a video that show where I believe air can easily get in.
http://motorbicycling.com/f34/new-grubee-skyhawk-cant-get-high-25583.html#post238401
Please let me know what you guys think about this.
 

cory151

Member
Oct 19, 2010
466
0
16
SoCal
I'm having this exact same bogging issue. I didn't find this thread in time so I made my own.
Some people have suggested it could be an air leak. I'm not very knowledgeable about small engines/carburetor adjustments, But I DO think the way this carb mounts/seals is extremely prone to air leaks. In another thread I posted several pictures and a video that show where I believe air can easily get in.
http://motorbicycling.com/f34/new-grubee-skyhawk-cant-get-high-25583.html#post238401
Please let me know what you guys think about this.
I posted this in your OP but that carb is garbage get an NT so you can atleast break that engine in right (if its a new motor).
 

cory151

Member
Oct 19, 2010
466
0
16
SoCal
Yea :-/ Where did you get your NT carb and how much was it?
Here you go buddy, I was in your shoes once but now I love my bike, dont let this little stumble bog you down. Youll switch your cable over and be done with it. .cs.


Well it doesnt seem to want to copy the whole link. but you know where to find them.
 
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sportscarpat

Bonneville Bomber the Salt Flat record breaker
Jun 25, 2009
1,844
485
83
california
I have ran the CNS on plenty of bikes and they ALL run fine. Better than the NT carb and I have run both. I hope to see CNS carbs coming up for sale on the used market. Just my two cents that is probably only worth a penny, if that.
Pat
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Well, I still have that 2010 CNS carb on the bench but the 3 new 2010 Skyhawk kits I ordered along with an extra NT are here so I'll let you guys know what I find next.
 

skiball83

New Member
Nov 18, 2010
136
0
0
41
Chicago
I have both an NT and a CNS stock carb that came with the GT-5 slant head. I notice no differance at WOT. If you can accually tune the CNS to your bike...I was fortunate enough to do this.....the only differance I noticed was slightly better mid range performance and by that I mean less 4 stroking. From what I have seen using both carbs on a stock engine...I prefer the NT. One less cable that cleans up the bikes apperance, and the performance is negligible. Maybe for a after market pipe/expansion chamber the CNS would be better but for a stock motor my vote is use the NT. I also think its more user friendly. Adjust idle and clip....thats it. No fumbling around with a/f settings to try and "readjust" for more power or a better running engine. The CNS started to make me crazy, the NT gives me time to enjoy my bike.
P.S. I will say this, the CNS is a better designed carb, for me it just wasnt worth the headache of running it.
 
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KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
Well, I am really frigg'n baffled now.

66cc 2010 GT5 with CNS carb.
I used black silicone sealant around the end of the intake and the rubber inside O ring.
I have a NuVinci programmable hub and I had it programmed to run at very low gears.

She seemed to run fine until I started gearing it up.
Now it has the same *&^*&% problem as the last one, no power at all, it just bogs when I put a load on the motor, and with my auto gears I never noticed it until now when I am trying to gear it up for speed.

It just shouldn't be this hard to make these carbs go.