Meddling with carburettor

Last few days of mine were lost into digging information about Fuel Injection and Carburettor and thankfully with help of some of my friends and netsphere I was able to get a good dose of knowledge.
P200 being a carburetted one I concentrated on carb mostly.As you might be knowing, carb plays a vital role in welfare of your bike's health.A detuned carb can greatly reduce the performance and efficiency.While a neatly adjusted carb can do wonders.
The fact also helps that carbs are much easy to tune/alter than FI.It doesn't need all that electronic gadgetry which FI needs. Once you get to know the basic hardware of carb its easy to do a makeshift operation on it in case anything goes wrong.
In my case the fuel efficiency had gone awry and engine was jerky in 1st and 2nd gear.When I enquired with some, it turned out that carb was set for too rich mixture(which meant it was forcing more than necessary fuel into engine).
Locating the volume control screw is easy.In fact its the only screw on LHS of carb other than the one for setting idle.Besides its bronze color so no mistaking!









As from the pic, I don't need to say the obvious, But will say it nevertheless!
Turning right the carb will channel less fuel and more air making it lean while turning it left will channel more fuel and less air(as in my case).
So adjust it accordingly.
However don't go overboard on either side. Maintaining it on a perfect position is best and will give you right amount of performance coupled with efficiency.
(Remember one thing turning it completely towards right or left doesn't mean peak efficiency or performance respectively) For engine's health you must maintain the balance.
There is one cliche though. Before you embark onto this learn to read your spark-plugs.Don't panic!!Its easy and a must know for enthusiast biker.
Remove both the sparks and check their electrodes for color.
If its more on the brownish side your bike is running on leaner mix if its way too much black your bike is running on rich mix. So ideally it should be dark-brown(almost black but not black!).
When you adjust the volume control ride the bike for a few kilometres and then check for color of the spark plugs tune it accordingly until your bike is running on balanced mix.
One more precaution to take- Don't turn the volume control like you do with normal screws.Do it slowly and only by half or a quarter turn at a time.Its much sensitive.

Q & A - My bike's fuel efficiency has dropped suddenly what do I do?

Seems like a pretty stupid question , and I am sorry for making you feel like one but the fact that various people all over face this problem and don't know what to do , lessens it's stupidity.
And another fact that yours truly himself asked this question , puts it into very legitimate terms, ahem!
So here we go.
I asked this very question to people who are in business and know much about such things.
Following is summery of what I got -
possible culprits -

1. The brakes.
2. Tyre pressure.
3. Clogged air filter.
4. Adulterated fuel or filling stations cheating you on quantity.
5. Riding style.
6. Spark plugs with incorrect gaps between electrodes.
7. Carburettor.

A very sedate list?Well thats what experts are, starting with basics and getting them right.
Now I go along the list and check for eliminations , Brakes? No the front disc seems to be in love with caliper :) or is it vice versa? anyway time to get it aligned.
*Tyre pressure? checked Ok and same for Fuel, Spark plugs.
*Air filter looked clean and well soaked.Besides If the air filter icon on dash is to be believed then there is no reason to clean it again. But then again I am not leaving any stones unturned and clean it as directed to me.
*Riding style? well now, time for self check.But considering the fact that my bike is only 2600kms old and me for one is not the type who thrashes his bike like anything puts me(or my riding) into safe perspective.
*Moving onto spark plugs.Opened both of them and checked their color.They showed a very dark brown almost black tinge.Indicating that my bike is running on rich fuel mix than necessary.
But the gap in electrode was perfect, so only cleaned them.
And ahh the fuel! yes there are some filling stations that do sale adulterated fuel and also fill in less fuel than your money is worth.So I filled in petrol from 3-4 places and right now settled on ESSAR.

Time for carb.One of the most important part.This little thing can turn things upside down if not set properly and also gives a very visible change in performance when tuned perfectly.
From my observation of sparks I had come to know that the carb was channeling very rich air-fuel mix into engine and that meant I had to control the fuel mix either by myself or by some mechanic.
As some of you might be remembering that I am far away from ProB showroom. And local mechs are such risky proposition, all this made me do it all by myself albeit with a helping hand from Sandeep and Mr.Venkat shyam of autoservice, Banglore(or bangluru...is that right?)

The whole thing as one can easily make out is vastly general and anyone can use it as a guideline on any bike or vehicle for that matter.
P.S.
**Prior to this the bike was returning about 34 kmpl.
**And now after all the trouble (which seems to have paid-off though) the bike recently returned 39kmpl.




-: Phantom menace.The fear is in the eye of beholder :-