Announcement

**niranjanvaidya** · 02-10-2009, 11:52 PM

Originally posted by chilled_fire View Post

Question : Can CO change in 2 days ??

Example : i got my bike after servicing(17k kms) on sunday when i asked they said CO was set to 3. now as i said before my bikes feels harsh these days which continued een after service so just outa curiosity i checked the CO today at petrol pump and it showed 2.07. so can this happen in 2 days (in say 150 kms ?) ? plz note petrol remains same - shell,
Can CO as 2 cause harshness ?specially at revs froms 6kRPM ?

Ideally, CO should remain constant if the fuel used is the same. I have noted that CO changes when one uses a different brew

I noted a similar harshness a few months earlier but it disappeared later.

My CO hovers around 2.85 to 3.25.

**chilled_fire** · 02-11-2009, 12:07 AM

@ caravikiran: thanks , makes sense, but still will get it checked at SC again on sat.

@Niranjan: yes, IDEALLY it shld not change as petrol is same but we all know with a 220 nothing remains ideal

Anyways my question remains, can increased or decreased CO cause harshness ?

**BANDHAV** · 02-11-2009, 12:18 AM

CO level can surely affect the way engine behaves.

By the way it may be discussed somwhere back in the thread but still i would like to know that whats the general understanding is about this concept of CO setting.

**caravikiran** · 02-11-2009, 12:36 AM

CO Setting :

Its a measure of how much rich OR lean the air-fuel mixture is.

1) More CO level = more fuel
2) More CO level = more air...

My take on what exactly is CO ?? One of the above must be true !!

Inclined towards the 1st one being the case.

**ravi@17bhp** · 02-11-2009, 12:47 AM

What is CO??

**BANDHAV** · 02-11-2009, 01:03 AM

@Kiran: You are right, but a little more elobration would help in developing better understanding.

@Ravi: CO stands for carbon mono oxide, this is one of the most harmful gas generated as a resuide of Internal combustion process.

Higher CO level shows that optimum level of combution is not reached.

**Praful** · 02-11-2009, 09:05 AM

Ravi and Bandhav, both of you are right!

CO = Carbon Monoxide

On a fuel injected bike like ours we don't have screws that adjust the amount of air or fuel entering the engine. Thus we need to rely on amount of CO that the bike is emitting at the exhaust. The amount of CO being produced is directly proportional to amount of fuel entering the engine. And variance in amount of fuel alters the Air-Fuel ratio. Changes to the Air-Fuel ratio will have a direct effect on factors like Harshness, Performance, etc!

This is as per my understanding, which might not be 100% correct!

Ideally speaking the CO once set should not change, this is as told to me by 2 PBK's. But we all know that it changes over due course of time. Reason simple hai yaar, the 220 will never do anything ideal, it will only do stuff thats weirder that ideal!

**rx100.7050** · 02-11-2009, 10:17 AM

Maza aa gaya

Pranay:
Thank you very much mate for the concern

Prafulji,
Touched 128 on speedo while coming to office on DND expressway. Could have touched more but relatively more traffic but flowing. So am happy again

Wanted to rip my bike.....did chota wheelies too

Feeling was good man. This gives peace man. Peace after what life throws at you

End of you people's emotional atyachar

**payeng** · 02-11-2009, 10:18 AM

From a post previously posted by Chilledfire (this particular post finds mention on the first post of this thread)..

Just when i thought i was loosing all hopes on PBK SC ... there was a ray of light.

I had send a mail in the morning to Bajaj PBK guys regarding the rear disc brake noise.and danm they were so quick to reply to all my queries i even got a call from pune regarding the same.

here is one imp answer we all were looking for.....

Question : "Also, I had a query, how come every time I change fuel the CO setting changes ?
I am now using shell and the bike is performing well, but previously almost every weekend when I used to check CO there used to be huge difference. Isn't the ECU unit supposed to handle the CO by itself ?
I have used Speed, Power and now Shell. "

Answer :

"I too wish that ECU should have recognised and then handle the CO on its own.

Unfortunately the mechanical changes of carbon built up insdie throttle body is not getting recognised by ECU.

Extra carbon built up do not allow correct air to flow inside engine.

That makes the engine to run rich disturbing CO level.

The ECU can be made intelligent by having few add on sensors and then an electrical motor can be triggered to control butterfly valve inside throttle body.
Such arrangement is available on many imported bikes,but the only issue is that it costs that much more !!

You can hope that ECU would be intelligent on our next new model."

So new models ahem, ahem

BY the way Praful, also have included your post on "What exactly is CO Setting" in the first page of this thread as well..

Originally posted by prafultripathy View Post

Ravi and Bandhav, both of you are right!

CO = Carbon Monoxide

On a fuel injected bike like ours we don't have screws that adjust the amount of air or fuel entering the engine. Thus we need to rely on amount of CO that the bike is emitting at the exhaust. The amount of CO being produced is directly proportional to amount of fuel entering the engine. And variance in amount of fuel alters the Air-Fuel ratio. Changes to the Air-Fuel ratio will have a direct effect on factors like Harshness, Performance, etc!

This is as per my understanding, which might not be 100% correct!

Ideally speaking the CO once set should not change, this is as told to me by 2 PBK's. But we all know that it changes over due course of time. Reason simple hai yaar, the 220 will never do anything ideal, it will only do stuff thats weirder that ideal!

**chilled_fire** · 02-11-2009, 12:12 PM

^^^ thanks Payeng, i was searching for this post of mine and the mails since 2-3 days

from above posts,
per my understanding, ideally CO should be 2.75-3
Now if this goes down to 2, like in my case, it means less petrol for explosion in cylinder, so ideally less power but increased milage.
but if CO goes above 3 say 4 which means more petrol , bigger explosion and much more power than needed and might damage the cylinders in long run.
So its very crucial to maintain the CO to the recomended value.
Please correct me if am wrong .

Will check this theory this sat, will go to SC and again set CO to 3 and then check the effects

**Aparajith** · 02-11-2009, 12:25 PM

Chilled fire, unfortunately IC engines do not work that way.

There is an ideal fuel:air ratio. It is 1:22 IIRC. So for 22 volumes of air, there has to be 1 volume of fuel present(any measurement be it ml, litres etc). If this ratio is altered u will not have a complete combustion.
If u have more fuel like a ratio of 2:22, then there is no air left for all the fuel to burn and all ur unburnt fuel is let out as HydroCarbon residue and Carbo-mono-Oxide. Please remember that the complete product of combustion is Carbon-di-Oxide. Even here ur bike feels choked gasping for more air.
If u have less fuel like 0.5:22 or 1:44, then there is not enough fuel to compensate the air and so it leads to a lean mixture which essentially is less power and also a damage to internal engine components due to excessive heating.

Hope I have made myself clear!!

**chilled_fire** · 02-11-2009, 12:40 PM

^^^ exactly , u explained it in more tech terms

bottom line , for 220s we need to get the CO set as recomended value anything above or below causes harm.

As PBK SC says thoda upar niche chalta hai .... they just need a bahana to avoid work

**pranay** · 02-11-2009, 12:48 PM

Some very informative posts here. Good work.!

**nitrosatya** · 02-11-2009, 02:14 PM

@ chilled fire:
do this in the morning before you set out for a ride.

Put your bike on main stand,
engage first gear,
let the wheel rotate freely for 1-2 mins,
the wheel will rotate with some jerks and some thuds in the chain area,
after it is done engage all the gears with little revving in between.

When the rear tyre gives no more jerks [generally in all gears] , you can then ride off. This makes my bike very smooth for the day. It will usually take 3-4 mins.

Do try that out!

And reply.

As per my observation,the vibes have something to do with final transmission part.

**chilled_fire** · 02-11-2009, 02:47 PM

^^^ yes i have tried this before not sure whether it works thou cause this process sounds strange.
Also, i do what Niranjan suggested , warmup ur bike for atleast 30 secs but not more than 45 secs

and it works most of the times.

With the first method - i usually am late to office everyday so can spend another 3-4 mins on it.

thanks anyways

Announcement

Pulsar 220 DTS-Fi

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment