Carb for 66cc Kit - Stock or CNS? Or other?

I

Intador

New Member
I'm fairly new to this forum, and looking to do my first build in the near future.
Because i live up Canada, my options are quite limited. Im looking at this kit

http://www.motorizedbicycle.ca/bicycle-engine-kits/grubee-skyhawk-gt5a-66cc-angle-fire-slant-head-bike-motor-kit.html

In addition, i will also be purchasing an expansion chamber.

So the question is, I'm contemplating buying a CNS carb to stick on there
http://www.motorizedbicycle.ca/aftermarket-parts/cns-high-performance-carburetor-kit.html

Will this increase performance, or just make things a nightmare? I've heard mixed reviews on it... and if it's a carb that i should not get... what carb do you recommend, stock, or another aftermarket one?

Thanks in advance
 
Stay away from the CNS unless you're a glutton for punishment. Stick with the NT or NT Speed carburetors. They are simple, easy to tune and will provide all the performance you can expect from a stock engine.

There are a few members who like the CNS but they have a lot of experience with that trouble prone carb and have seemingly mastered it. For most, the NT is the better alternative. And there is nothing to be gained by using the CNS. The performance will be equal to, or less than what you'll get from the simpler NT.

Tom
 
2door said:
Stay away from the CNS unless you're a glutton for punishment. Stick with the NT or NT Speed carburetors. They are simple, easy to tune and will provide all the performance you can expect from a stock engine.

There are a few members who like the CNS but they have a lot of experience with that trouble prone carb and have seemingly mastered it. For most, the NT is the better alternative. And there is nothing to be gained by using the CNS. The performance will be equal to, or less than what you'll get from the simpler NT.

Tom
Click to expand...


^^ This. ^^


Even though I have a CNS carb & have made it work for me, I'd not suggest one for the neophyte. They tend to be 'finicky' in their settings.

Best of luck in your upcoming project!!
 
They are fine, I have used them on lots of builds (be aware you can get the same carb for $25 shipped on ebay) But its not a terribly dramatic increase over the NT. In fact, if your engine is stock or slightly modified, you probably wont feel any difference at all. A properly tuned NT carb (with the jets / needle tuned) will rip. They regularly pull 40+ mph on modified bikes.
 
I like the cns due to the fact I can tune it just like I tune my mikunis on my bandit 1200. Idle circuit, pilot circuit, low speed needle and high speed jet. Once u understand how and when they work, very customizable.
 
Listen, if you do no other mods and just slap another carb on, your improvement will be nothing or possibly negative. I say do the good two stroke things, dial in the NT carb with the proper jet, expansion chamber, match the ports/manifolds, air filter, raise the compression, new CDI, etc - all very easy things. Enjoy the power - the carb at that point still won't be the limiting factor.
 
I've found that with my setup, the #66 jet seems to work the best in my CNS......just a very little 4 stroking at high RPM cruising.
 
Intador said:
I'm fairly new to this forum, and looking to do my first build in the near future.
Because i live up Canada, my options are quite limited. Im looking at this kit

http://www.motorizedbicycle.ca/bicycle-engine-kits/grubee-skyhawk-gt5a-66cc-angle-fire-slant-head-bike-motor-kit.html

In addition, i will also be purchasing an expansion chamber.

So the question is, I'm contemplating buying a CNS carb to stick on there
http://www.motorizedbicycle.ca/aftermarket-parts/cns-high-performance-carburetor-kit.html

Will this increase performance, or just make things a nightmare? I've heard mixed reviews on it... and if it's a carb that i should not get... what carb do you recommend, stock, or another aftermarket one?

Thanks in advance
Click to expand...

brnot this is the best carburetor Iv'e found it's off a Honda 80cc scooter,The cns race carb w/the choke cable is not the answer, although they work the best they break Iv'e bought and broke 4 or five, so my suggestion is just like the other 1 stay with the stock carb till you get going, if your guna do a pipe well learn to braze first and get oxy acet tanks.
 

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ken murphy said:
brnot this is the best carburetor Iv'e found it's off a Honda 80cc scooter,The cns race carb w/the choke cable is not the answer, although they work the best they break Iv'e bought and broke 4 or five, so my suggestion is just like the other 1 stay with the stock carb till you get going, if your guna do a pipe well learn to braze first and get oxy acet tanks.
Click to expand...

Try to stay away from that offset intake to, I havn't had m
uch luck w/that either.
 
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stick with the stock carb, tuned for your engine AFTER break-in.
The tuned pipe is a good first mod, but I'd avoid the cns or ANY aftermarket carb until you have more experience tuning.
 
Delorto is great with a standard motor, and with the right jet needs no other adjustment.
However on a modified motor I find the speed carb is superior. The Delorto just didn't match the pipe and would 4 stroke no mater what jet I tried. The best carb that I have tried so far is the 15mm barrel carb from a 49cc piston port scooter motor, The needle adjustment is often Loktighted and can take a bit of effort to release, but a very easy carb to tune, and works great with my motor pipe combo, 9500 Rpm 80 Kph.
IMG_3877_zps38fdbd48.jpg
 

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In addition to the expansion chamber, i'll also be buying a ported exhaust manifold, and possibly a jaguar ignition. I've heard alot of people say they get better throttle response with the JNMotors Performance Carb, but it there really that much advantage to be had with it over the NT Speed?
 
Depends if you can tune a carb?
If so I'd stick to the speed carb with an expansion chamber, that's been my experience.
Others may have had better 'luck' with a 'Delorto', if that's the one your talking about.
I've had no experience with the 'CNS' style carbs, however I do like the idea of a tunable idle circuit, but I use to tune VW carbs, with air bleed, mixture and 'idle'. And it may not be for everyone.
I was getting close enough to 50 Mph with the speed carb, but if you are trying to get ultimate Top end, Bigger is better.
 
ken murphy said:
Try to stay away from that offset intake to, I havn't had m
uch luck w/that either.
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Wow to each hos own I guess lol

I get the best preformace out of all my china girl builds without reed conversions by running the cns and a long offset z intake ...... Dead srs .... The steel long z intale is a 16mm bore ... Exactly the size of the cns carb venturi and with a good port and polish the volume of the longer and larger bore intake helps out witj torque imo. I found this setup to be better once properly jetted than a shorty intake and a dellorto sha or phgb of equil size .
 
Agree.
I made my own offset manifold, and someone told me it would make my motor run on?
Nope, just gave better lowdown.
 
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