First, of all your problem is not with AFR but with air leakage. No matter how much improperly the AFR is tuned, then also your rpm will not shoot by more than 500 rpm. My bike idles at 1000 rpm when cold and 1200 when hot.
There are three possible causes of your problem. They are:-
1. Air leakage from around the carburettor. Check connection between carburettor and head.
2. Tight tappets. Was your tappets adjusted, then a tight tappets can cause this problem.
3. Battery problem. If your battery is undercharged then also you will get the same problem.
Regarding carb tuning i am posting again and all members in this thread please note the same:-
1. Pull out the air pipe between the carb and the head. You will see that a rubber pipe is fitted to carb insulator. Pull it out.There will be a brass pipe. Close it with your finger. If you do not close it your bike will not idle.
2. Now set the mixture screw to 1.5 turns out.
3. Now start the bike. Be sure to close the air injection at carb insulator with thumb of your left hand.
4. Now increase the idle by idle screw to 2000 rpm.
5. Now slowly turn out the screw. I repeat very slowly.
6. You will see the idling rising. continue until maximum idling is obtained. Beyond a point idle will not increase at all and instead decrease. At the point where idle is highest stop turning the screw.
7. You will see your idling is highest and also the rpm needle is constant.
8. Now decrease the idle to 1.2k. stop the engine.
9. Now remove your finger from carb insulator and connect the air injection pipe.
10. restart engine and check idle.
WHY TO REMOVE AIR INJECTION AND CLOSE THE PIPE?
The air injection in extreme works on pulse and injects part of exhaust gas into inlet to control NOX emission. But this dilutes the mixture and thus proper tuning is not obtained. SO remove it from carb insulator just after carb and before head. After removing close the hole as your bike will suck air and not idle. Also in this type of carb if you do not remove the air injection pipe then your idle will not decrease after some turns of screw out. If you remove the pipe, you will see that after idle increases to highest if you turn screw out then idle will decrease. If the air injection is connected then idle will not decrease no matter how much you open the mixture screw.
How to know mixture is set correct?
When you turn the mixture screw out, you will see the idle will increase. At one point idle will be highest. But there is a catch. Check how the idle is highest. At one point the idle will be highest but bike will be smooth. At slight another point, idle will be highest and bike will vibrate. The point at which idle is highest and bike vibrates, that is the correct setting.

Carb tuning is not easy. You must have read that there is no substitute for experience. This applies to carb tuning. Ask SHOEB, he was also not able to get correct tuning. It was until he asked me several times and i explained him each and every detail in minutest possible way. There is no fixed turn which works for all bikes. You have to find your bikes work at which setting. So follow the above steps.

Factory tuned doesn't means perfect tuned. My mechanic tunes bikes and even company cannot tune like that. Yesterday i tuned my extreme from my mechanic and believe me it has become so smooth that you will feel like unicorn. Before this it was in factory tune. Yesterday first time my mechanic tuned and my bike feels much better than new.

Thank you very much for that guide Sibun. I just need to find exactly which pipe you're referring to now.
Also, I changed the Spark Plug on my bike. The Authorized Spare Parts Dealer gave me an NGK itself. CPR8EA9. Exactly like you'd specified. I installed it immediately and it felt like there was an immediate difference in how the bike behaved. RPM no longer varied as much as before. Better, but can be still better. Couldn't check the plug after riding as it was already dark.

Will try your tuning guide sometime soon and revert back here.

You are explaining to all in detail in the minutest possible way how to “tune the carburetor” (actually it is not carburetor tuning but altering the air-fuel ratio) and getting it done by an experienced mechanic on your own bike. Why don’t you do this “tuning” yourself on your own bike as you are experienced and knows exactly how to do it?
(Just out of curiosity; not to insult you or any others).

That's what Sibun wrote in his post- carb tuning/afr adjustment comes only by experience.
Also,In his previous post he mentioned that he would ask his mechanic for the easiest method to adjust the AFR/Pilot screw of CBZ.
If you ever get time,please go through the splendor thread. He also posted a picture of his spark plug in that thread which was just looking as if it was used in a FI bike.

But it really is strange that it is advised to those who even does not know which screw to be turned.

Correct. But what about those “tuned” the carburetor prior to it?

Do you believe the carburetor plug reading is correct especially nowadays when we get unleaded fuel? And as far as I know, even the procedure advised to taking out the plug to check its color is not proper.
Anyway, I don’t think I will get enough time to go through the thread you mentioned.

See for yourself, http://www.xbhp.com/talkies/motorcyc...tml#post901377

The air injection in extreme works on pulse and injects part of exhaust gas into inlet to control NOX emission. But this dilutes the mixture and thus proper tuning is not obtained. SO remove it from carb insulator just after carb and before head. After removing close the hole as your bike will suck air and not idle. Also in this type of carb if you do not remove the air injection pipe then your idle will not decrease after some turns of screw out. If you remove the pipe, you will see that after idle increases to highest if you turn screw out then idle will decrease. If the air injection is connected then idle will not decrease no matter how much you open the mixture screw.
Sibun, is this typo error? I beleive it is fresh air from Air filter injected in to inlet to reduce emission.

No, insult taken. Instead i am happy that you asked for it. Regarding tuning on my own bike i always tune my own bike and also my friends bike. i have tuned from so many years that by just starting the engine and hearing the idle, i can tell you if the mixture is correct or not.
But since i have to tell my fellow members how to tune the bike so i thought it better to tune the extreme from my mechanic once and observe. because i know he will set the perfect mixture setting which even mechanics on CO machines cannot set. As i told experience is something which you cannot replace. I will tune carburettor and bike will run very good and mileage will also be very high. But he just gives that fine finish over something that is perfect.
No fresh air is injected to exhaust side to reduce CO to CO₂. Exhaust gas is recirculated in order to reduce NOX emission.
Also the CV carburettor works on principle of vacuum. So if the secondary air injection is connected to the carb insulator then it will continue to build vacuum even when screw is opened after maximum revs position. So unless you are expert, you cannot deduce the position. So by removing the pipe and sealing the entry, you can get correct tune. Even you can look at the tachometer and tune. At the point where tachometer needle is at highest, stop turning the screw. But tune very slowly and allow engine to respond. When the engine attains highest rpm stop turning further. The point where the Rpm is highest is the ideal setting. So after that point if you turn the screw out the mixture will get rich and if you turn the screw in the mixture will get lean. So in order to get perfect setting we do these methods. Do not worry, you will be able to do it. But turn screw very slowly. As soon as you get high rpm and rpm do not further increase, just stop further twisting.

Today i had tuned my carb of my xtreme to 1.6 turns from the closed position,and had set the Rpm to say 1500 at hot when it is kind of cold it is 900-1000rpm..
But my problem is when i stop at the signals ,the bike suddenly stalls......And after restarting it doesnt responds to the accelerator suddenly but after initial gap of 2-3 secs....
The main reason for my tuning was that my bike's Air filter and Spark plug were changed in the last service and was giving me a mileage of 37kmpl after that.....
Can anybody help me with the issue i m facing dont know what to do????

please some one post the DIY for fitting xenos

Motorcycle/Bike Alarming Security System From XENOS | eBay
I am going to buy it but iff i can fix it myself.

Hey Sibun, Can you PM me the address and name of the mechanic who tunes your CBZ in BBSR ? I'd like to take my bike to him and do a thorough check of bike. Since, I live in Kendrapara, it won't be difficult for me to reach him.

Same happened to me after i did service in a outside mechanic. I wanted to tune at that condition only,but when i tuned as u did,it stopped on traffic signals and when i readjusted it to 1500 after i some time i noticed that IDLE RPM is shooting around 2500 :O. I was confused why this readjustment is required. As per sibun air is leaking somewhere or tappets are tights. I was not having this problem before that service. i would try after increasing 0.25 turns today.


If u want to Fix it urself DO IT URSELF. Buy itnd see if it comes with a manual or not(most probably it will).most crucial part would be the one with ignition lock wiring other than that there shouldnt be any problem to u. Or u can ask a local mechanic to do it for you and while he does it,u can learn how to do it. BUt if i was you i would havee done all by myself,search google or any other biking forum u must get the proper way to install it. let me see if i can arrange one for you.

Kendrapada is my maternal uncles place. Regarding my mechanic, i will send you my number in a PM, the day before you come to bhubaneswar, you call me, i will accompany you to him as he will pay special attention if i am there. Also we can meet.
If your problem has started after doing the works, then check two things:-
Air leakage from intake manifold due to improper mounting of carb.
Choke cable routing. Improper routing will cause choke to be in on state.
Go to the same mechanic and tell him to correct it. You have paid him and his responsibility is to cure your bikes of problem. Go to him and politely explain, he will do the needful. Do not worry, most here always change mechanics always, but i would advice you to go to same mechanic as he doesn't know what your problem is. Go and explain him and he will do it for you.

Firstly, give a sudden blip in the throttle while at neutral, and if the engine shuts itself, then u r running very lean. and that's what causing those stallings in the traffic.
If not then u need to set ur IDLE rpm a bit higher. Set it close to 1.3K wen cold. that should do. even if still stalls, then set the IDLE at a little higher Than 1.5K when it has stalled. (No doubt u need to have a screw driver at that moment)
U need to set the idle at 1.3-1.2 K when cold, so that when hot, it reaches around 1.6-1.8K (max).
check, when ur idle goes to 2.5K , does it come down when u give 1st gear and release the clutch slowly, without giving any throttle!! If yes, then u r running RICH.


To all - if u are doing a tuining DIY, and u hardly have any previous experience, then I must tell that tuining takes a hell lot of time.
It's tune, ride and check, then again tune ride and check and keep going till u are completely satisfied.. I recently did a satisfactory tuinin in my NS, and it took me abt 45min to come to a satisfactory setting.!!

couldnt post for a while my motherboard died i should have posted for guidance here first before i did this like sibun said but i suddenly decided to do it lol . This is the first time i remove the tank by myself and when i carefully removed it i see this pipe like think at the bottom and decided to open it to see waht was inside .It has some kinda filter with a o ring on it....cleaned it : It had some kinda impurities inside after i removed the filter :



The filter after cleaning :



Hope i installed everything back correctly...took a test drive all seems to be fine for now :P .

Also sibun how to remove this air pipe ? i tried to but it was too tight and the metal lock only moves side to side couldnt open it ...afraid i might break something i left it alone .



from another angle :



If i can get that hose removed then i am one step closer to adjusting the tappet myself .