Cns carb tuning VIDEO request

G

GreedyRogue

New Member
I am looking for a video to help me tune my cns v2 carb.

I did a google search and didn't find any videos regarding the cns carb. If anyone can point me to a video, that would be great.

If one doesn't exist, maybe someone would be kind enough to make a video to teach us how to tune these things. Might cut down on the "HELP carb bogging" threads.
 
I myself could not find a video either so I used my 1970's motocross exp. to tune mine.
1. I adjusted the idle with the idle and air screws.
2. The e-clip controls mid range.
3. The main jet controls wot
After I made any changes I did plug checks to make sure I was going in the right direction.
 
The problem with these CNS monsters is that to get by the EPA, they're jetted so lean that they barely run. Sick bike parts should really put together a 'CNS fix kit' with some jets and so forth.
 
I don't think the jetting should be too much of an issue. (maybe just in my case)

I have a fellow MB rider here in town who is great at tinkering with engines. He came over and had the carb tuned within 15 minutes. Problem is by the next day it went out of wack already.

I rode to a nearby store, ran great no issues. From the store home I had to put it on full choke to keep it running over 13mph.

Obviously noone messed with the e clip or the jet while I was in the store, yet over 1/2 throttle I had to have it fully choked to keep running.
 
I have checked for an air leak using carb cleaner. Checked the carb to billet, billet to body, checked head bolts, I have literally covered the thing in carb cleaner and no revving or bogging.
 
Tell a little more about your set up, which air filter what oil mixture what spark plug and how many miles.
 
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Ok, Stock setup, no after market parts.
Stock air filter
40:1 dino oil in 87 octane
My kit came with a 3 prong spark plug, not sure brand, but I can pull it if you don't know what one I am talking about.
Currently 350 miles on the motor.


However, I did possibly fix it today. I removed the upper "vent" tube completely and it went from bogging past 1/4 to running ok-decent, with no other tuning. Yesterday it ran like crap, only thing I did was remove the tube and big improvement.

Still needs tuned a little more but she is doing 200% better.
 
Removing the vent tube was one of the things that worked for me, I use a auto type trim barb to seal the hole in the filter base.
 
I kinda worried about something getting sucked into the vent that I took the hose off of. Might look into a wire mesh cover so it can still breath but not suck anything in.

Especially rain.
 
A small gas filter for a weed blower works good on the vent also. Do not plug off the brass vent barb, fuel will not flow into the carb. Thats what the small filter is for. Just make sure you use a filter that lets air move both ways, some of them have a check valve in them.
 
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