Query approved.

I think your bikes idle rpm should be set around at 1400rpm. Set it when the engine has warmed up.
It should solve your problem, if doesnt then you have to tune the slow speed jet.
100- 200rpm fluctuation is ok, though not a big issue. I think this fluctuation will be there if it is tuned for optimal range.
If the svc cudnt solve then it is the slow speed jet, try with the idle rpm screw first.
And its time to change your Engine oil.

Shahriar - does this happen when you keep throttle at a constant position also? Does this shut off happens randomly without any pattern? When this happens, do you feel that CBZ is running out of fuel?

Next time this happens, simply open the fuel cap & close it & start the vehicle & post me the result.

it used to go at 1.4k rpm when i run it constantly in the range of 90-100kmph and redlining it for sometime.but in this winter it doesnt go above 1.2k rpm. well i have tuned it now. after ripping it for quite sometime i set the idle rpm to 1400rpm. now the bike doesnt shut off.
about the fluctuation......what do you mean by optimal range???svc guys tuned my carb for mileage ( around 2turns anticlockwise from full close)...engine heated up very first & i could see1.5k idle rpm even i ride it normally & also fluctuation was there. then i tuned it myself (around 3.5K turn) though needle fluctuates a little but engine is very calm now and getting greater pick up.

nope it doesn't happen when i keep the throttle constant.it doesnt feel like running out of fuel. after setting the idle rpm a bit higher problem is solved buddy

many thanks to all of you for helping me & thats why i keep coming back to Xbhp whenever any problem is there.......

Tuning for mileage means the air-fuel ratio (AFR) is tuned to be lean, that is, in this ratio air for combustion is supplied more than required quantity. So fuel intake is less and hence more mileage and this heats up the engine fast, not good for the engine.
'Optimal range' stands for the correct air-fuel ratio which provides the perfect blend of mileage and performance.
When lean you will your bike to be smooth and when rich you will feel roughness and more power.

I think the tuning you have done might have made the AFR rich (more intake of petrol than required) though am not sure.
You can check yourself by listening to the rhythm of the exhaust.
Let the bike get warm enough. then try the two steps.
-When you raise the throttle 1/4th and leave, and you hear bursts (like small crakers) then its a rich mixture. A hollow burst indicates a much leaner one.
-go take your bike high on the road (be safe) rip it a little till you reach the final gear move a little more, leave the throttle instantly and completely (allow the engine to brake) dont brake manually, if you hear bursts from the exhaust like crackers then itz a rich one.
Getting optimal range will take experience in tuning...
But sure try it if you just remember the default no: of turns, if you are careful with the screw (main jet) (it can get damaged easily) and if you know the rpm to be set to start tuning.

actually i tuned it many times....i tuned it for both mileage & performance....getting to top speed is a piece of cake (110kmph) & also getting 40-50kmpl ( depending on the riding pattern). i dont know the default setting of the carb, coz when it was new svc guys tuned it & i was getting slower throttle response thats when i started to play with the A/F screw and i always wanted to have a rich setting rather than lean setting.

can you tell me what is the default setting of cbz xtreme's carb i mean default turns of the a/f screw anticlockwise from full close???? i'll be very helpful.
i'll definitely check out the sound as you mentioned.what do u mean by hollow sound & craker sound? how it might sound???

bro one more thing 2days ago i was draining oil of my bike then a person came & started the bike it was just one twist & i didnt notice.will it cause any damage????



Thanks
Shahriar
bangladesh

@ARNandal: bro, tht's a very interesting piece of info. I might try checking for my P220 FI. Can you tell me how to find out the A/F screw in my bike & what's the optimum setting for AFR for it?

@Aargee: dude, wht's the trick in opening petrol tank cap & shut it again. U mean, some air pressure to work inside, to force the fuel down or something?

Pls check all my posts on this thread - http://www.xbhp.com/talkies/help-me/...e-highway.html

@arrgee: yep...I got your point..."Clean the fuel lid & remove the impurities & you can see the difference." Will check the same for my bike as well.

Making a rich setting is ok, but Too rich can do bad to your bike as fuel intake will be more than required so the mixture wont get burned completely hence will result more unburnt particles and carbon deposits. optimal range is enough for a good throttle response.

Sorry bro am not familiar with that, and sometimes it wouldnt be that exact in every case. I own a pulsar 180ug3 and its said to be 2&1/2 turns for my bike, anticlockwise from not so tight, but it doesnt suit mine.
May be your SVC can tell you.

hollow sound (too lean setting): here the pitch of the sound will be more and the burst-sound duration will be more. the sound a bit similar to that when we remove an airlock from a water tap, by just closing it for a few seconds creating a pressure inside and leaving it all of a sudden.

Cracker sound (too rich setting) : something like phatt phatt similar to crakers.. these bursts have small sound duration and the interval between consecutive bursts are less.

lean/rich setting can be identified by examining the spark plug after 30kms of the same setting. white deposits indicates lean, black for rich, reddish brown for the correct ratio.

No, not if itz just once. itz the same idea similar to running a bike without oil, no friction busters so more wear and tear, so can damage parts. no prob if itz just once or twice.

@JonnyRider: Bro, your bike is a fuel injected one (FI), so it doesnt have a carburetor. tuning is a different process in your bike.
Am not familiar with the FI tuning. But as far as i know itz not safe to meddle with unless you have some prior experience, or else you might end up damaging some parts related to it.
It would be better if you open a new thread asking how to tune an Fi bike, it might be informative for many members here including me. I couldnt find any threads regarding that here, the moderators will guide you if you too couldnt find one.

Same problem with HH Hunk!

Hay, let me share my same experience with HH Hunk. My bike was running fine till it clocked 17000KM in the odo. But in this winter my bike has devloped the weired problems like you faced, like stalling of the engine in the traffic and fluctuations of RPM. I reported this thing to the service centre but they fixed the problem for a while. From the next day the problem was very much prominant. On 2nd Jan, I had a ride of 550Km approx (both way), and I rode the bike at around 8k to 9k rpm mark and I could feel that at high speed the engine is stalling for a second and coming back to life.
The SC did all to prevent that issue, like the Carb overhaul, spark plug test etc.

But few month ago I had a ride and I rode my bike at 6.5 to 8k rpm and the bike was just fine. So is this the problem due to higher rpm run? May be the engine is not devloped to run in that RPM.
Now I have kept my bike in a side of my garrage and planning to get another one.

my bike stalled because of lower idle rpm & since the svc guys tuned the carb, my rpm needle always fluctuates but only a little.i too go for trips every month which is approx 500kms and i usually ride between 7k to 9k never faced problem like you faced. but my bike chokes over 9.5k like no fuel maybe the rev limiter comes into play then. i dont knoww what is your bikes exact problem. there are more expert people here who can definitely help you.....thanks

I dont think so. 9k is fine for your bike.
If you are sure that you had sufficient petrol and you had the fuel tap adjusted to either ON or Reserve. Then it might because of some impurity in petrol or your carburettor might have had some impurities.
And what is you idle rpm in winter? you would need to set your idle rpm, it wouldnt be the same as you had set in summer because of the atmospheric conditions. Ride your bike enough to get it warm then set your idle rpm at 1400rpm.
That would have did the job.
If not then your bike might have run lean.