CNS Carburetor

theycallmebob

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Dec 13, 2008
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Gainesville, FL

MB-Monkey

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Nov 19, 2008
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Manchester TN USA
I have one of those carbs and it is worth every penny. It is defiantly a larger Jet a better Air Filter but what makes the carb is the Air/Fuel Mixture adjustment screws.

Saying all of that.......

when i went to install the carb in the frame there wasn't enough room to clear the back frame.

It comes with an additional spacer mount for the rear of the motor kit which will change your chain length.

I had a custom 90 Intake made for me for 20 bucks so the carb hangs off of the side of the motor. It clears the cranks just fine but kind of blocks your foot on the up stroke i just set my foot to the outside of the peddle and it works fine.

Once you get passed break in and adjust the mixture and idle it runs much smoother than the stock carb

There is my experience for ya dnut
 

theycallmebob

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Dec 13, 2008
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Gainesville, FL
I have one of those carbs and it is worth every penny. It is defiantly a larger Jet a better Air Filter but what makes the carb is the Air/Fuel Mixture adjustment screws.

Saying all of that.......

when i went to install the carb in the frame there wasn't enough room to clear the back frame.

It comes with an additional spacer mount for the rear of the motor kit which will change your chain length.

I had a custom 90 Intake made for me for 20 bucks so the carb hangs off of the side of the motor. It clears the cranks just fine but kind of blocks your foot on the up stroke i just set my foot to the outside of the peddle and it works fine.

Once you get passed break in and adjust the mixture and idle it runs much smoother than the stock carb

There is my experience for ya dnut
Great information!

Did the kit come with any sort of instructions? Did the new throttle/grips have an integrated kill switch or will I need to pick one of those up as well? Would it be a bother to snap a shot of your custom setup to make the carb work?

I was gonna buy a new k&n air filter, but at 38 bucks its not much more to just get the knock off filter and a better carb while im at it.

Thanks for sharing your experience.
 

MB-Monkey

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Nov 19, 2008
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Kit didn't have any instructions but it did come already assembled however if you look at the Grubee site here

PLEASE READ THESE INSTRUCTIONS BEFORE INSTALLATION

It has the instructions and some info on it.

the throttle did have nice upgraded grips with an integrated kill switch mine sticks a little from time to time but i hear that is a common problem

I will try and snap a couple of shots of my setup once the sun comes up today but no promises.

Just having the air/fuel mix screw is worth the upgrade IMO
 

MB-Monkey

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Nov 19, 2008
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Manchester TN USA
I just finished editing the pics so here they are not the prettiest intake but it works.


The pics show the carb make sure if you make a custom intake that it clears the Clutch arm mine is very close but it sit just above the mark and the clutch works just fine.

Also i would recommend polishing the crap out of the tube to help with airflow but this setup works just fine

As i said before just having a air/fuel adjustment screw is worth the price but the remote choke is a bonus.
 

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MB-Monkey

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Nov 19, 2008
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Manchester TN USA
To be honest i am still fine tuning everything in but what has worked so far is to start the bike allow for warm up before any adjustments. unless it is racing then back the idle down. After warm up...

1. raise the idle up some to allow it to breath

2. adjust the Air/Fuel adjustment screw in (clockwise) until the motor begins to stumble.

3. Back the screw back out 3 full turns (anti clockwise)

4. Lower the idle back to normal rpms

These settings make for a rough cold idle but IMO thats the sign of a proper warm motor setup use the first setting of the remote choke at first.

Saying that take in mind that i am in Florida and nearly at sea level but those settings should get you close enough to make fine adjustments. I have noticed a big difference in performance mainly in middle rpms i don't really run WOT i keep it in the power band like a 2stroke wants to breath. Higher altitudes will run leaner than lower altitudes i believe but we all love to tinker so make an adjustment try it out.

I use a felt tip pen (sharpie) to mark settings i like on the carb body makes for easy setup as temps can vary 30* in 24 hours

DISCLAIMER
I am not a professional mechanic and this information can in now way be held against me. I live by the creed if you don't know what your doing a $5 tip normally gets some help from someone who does.
 

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stuartracing

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Dec 9, 2008
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Gainesville FL.
Hey I`m in FL. too, so it`ll prolly be about the same settings....Thanks that helps to get a base line...I have a PIPELYNE exp. chamber pipe so gotta adjust for that too....
 

misteright1_99

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Mar 21, 2008
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Treasure Coast, Florida
My experience with tuning carbs has always been to get the engine warmed up and idleing, turn the screw in till it starts to stumble, this would be the rich setting, turn it out until it reaches the max rpm, this would be the lean setting, then turn the screw in 1/2 turn.....
 

theycallmebob

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Dec 13, 2008
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Gainesville, FL
Even more info now, thanks Huffy.

It looks like I'll have to figure out something similar to your setup if I want to get the carb to fit the bike, or try the mount spacers. I also ordered a 34t sprocket so I already have to adjust the chain length, it'll hopefully have enough left over so I don't have to add to the chain.

Thanks again, hope to be adding my thoughts on the carb in this post as well.
 

stuartracing

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Dec 9, 2008
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Gainesville FL.
I just got my cns carb today....Mine has a line going from the float bowl to the venturi/intake side of the carb...I`m assuming it`s a secondary jetting system(wide open only)....Mounted fine except for the filter...I don`t want to move my motor, so I`m waiting for a shorter intake tube to come it....I hate moving these motors around,seems like if they work good, no broken bolts then leave it alone...You do any one thing to them it changes 5 other things,lol....
Paul...
 

stuartracing

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Dec 9, 2008
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Gainesville FL.
oooops....About the line going from the float bowl to the intake of the carb....It`s just a drain/vent tube.....When it got here they had the line plugged into one of the ports on top of the carb. going down to the bowl....Sounded like a cool idea though,lol.....
 

MB-Monkey

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Nov 19, 2008
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Manchester TN USA
after having an issue with my cns carb i have done some more research on them. On my carb body it is printed HongHua and pz15j the original application was for the Yamaha Cy-50 and CY-80 "scooter"

I would suspect that yamaha would be able to get a rebuild kit for the carb if necessary but i have not contact them yet. It was rainy here today so i have not removed my carb yet but i am going to take it off and dissect it and take some addition pictures of the inside of the carb once i get it swapped.

the specs from the chinese manufacturer read as

最大功率: 4.9KW/6000r/min
最大扭矩: 8.0N.m/4500r/min
经济油耗: 1.9L/100Km
发动机最低稳定转速: 1500±150r/min

And yes the tube was hooked up on my carb as well but it is just an overflow drain on the bottom
 
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