CNS Carburetor

theycallmebob · #1 01-03-2009, 10:03 AM

I was perusing the Spooky Tooth website and came across there CNS Carb. The description isn't clear whether or not the carb is a performance upgrade or just a replacement for the OEM one on my chinese 80cc in frame kit.

Anyone have any experience with this setup? Im looking for a slightly better carb for some added power and response.

Thanks.

Spooky Tooth Cycles - Motorized Bicycles: Gas Powered and Electric Bikes - CNS Carburetor for Motorized Bicycles

MB-Monkey · #2 01-03-2009, 11:03 AM

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

theycallmebob · #3 01-04-2009, 12:25 AM

Quote:

Originally Posted by HuffyCruiser

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

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 · #4 01-04-2009, 03:29 AM

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

stuartracing · #5 01-04-2009, 03:13 PM

I have a CNS carb. coming.....Can`t wait for it to get here....Thats some good info about the carb....

MB-Monkey · #6 01-04-2009, 04:42 PM

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.

hiker472 · #7 01-04-2009, 05:18 PM

Wow! I can't believe the price on that thing!! Only $50???

I'm definitely going to get one of those for mine!

stuartracing · #8 01-04-2009, 06:23 PM

Got any tips on adjustments????

MB-Monkey · #9 01-04-2009, 07:00 PM

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.

stuartracing · #10 01-04-2009, 08:14 PM

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....