Query Approved

You can down jet your bike but engine life will suffer (not recommended).
And for mileage don't exceed 3k rpm. You'll surely get amazing mileage.
Btw what mileage do you wanna get?

Well apart from riding slow what i can recommend is a sprocket change..

You could replace your front sprocket (or rear, whichever's available) with that of another bike.

Go through this: http://www.xbhp.com/talkies/universa...sprockets.html

If they're not too expensive, you could get the sprockets for another bike...

1.Reduce Ur CC (plonk in an CBZ piston)
or
2. increase ur compression.
or
3.Ride slow/ change ur riding style.
or
4. smaller or lighter tires .
or
5. WHat kinda FE are u expecting? 50 from a zma in city?
or
6. Lighter sprokets
or
7. Lighter stator coil/ magnet assembly from CBZ
or
8. take the public transport
or.....
9. change ur exhaust , its too heavy , Lighter exhaust , breathes better and improves FE inturn
Im bored of so many options... :-P

Santa

Some serious mods there
Learnt new stuff but i'm sure the whole point here is to spend less money

the troubles will make you stronger brother, face it with courage, if you love your bike so much love it as it is...don't modify it for the sake of FE...I would suggest you not to use the bike till you come out of the crisis which I believe is temporary...
if the distances you commute are small use geared bi-cycle, now bi-cycle is a style statement at least here in b'luru . Cycle will tone up your body (a strong body means strong mind), no fuel, you save environment ...

simply tune it for lean mixture, i.e. less power, more mileage.......by tunning it for lean mix.......you can increase the mileage by approx 5kmpl.......but your engine will run hotter.......so engine life might be reduced along with spark plug life...

WOW! You want just opposite what I want man!
My 2011 Karizma - R covered Siliguri to Kolkata(600km) at a stretch with only a full tank fuel. I was so scared, as I am not interested to ruin my engine for millage. I once again tuned the carb(by the SC people) to make the mixture rich. though my mec told me that the tunning is perfect. I checked the spark plug color, it was light brown.

But later on, I have analysed and came down with few points that may have contributed for better FE.

1. I was riding consistently at 60 - 70 - 80(max) kmph, without hard acceleration and even hard breaking(used engine breaking and then used the front & rear breaks softly).
2. Fortunately or unfortunately, I was using 3 to 4 psi more air pressure at the rear. Which I noticed after I reported the weired millage issue to the SC.
3. I changed the spark plug to NGK Irridium before the trip and Motul - engine oil.
4. I filled up the tank till the neck after I crossed Bagdogra(15 km from Siliguri) and the fuel was xtra premium
5. To me, the 2011 Karizma - R is having less weight(Its my personal feeling) with the same engine.

I am still thinking how this was possible...........!

ZMA are already in lean tune in stock form...unless the Air Filter chokes up no ZMA runs at rich AFR...some ZMR owners have reported 50 Kms per Liter..
and most ZMA-R owners get 35 to 40 in stock form in city...if you lean it any more the engine will heat up and wear quicker...
Best to modify driving habits and get better FE..
Remember it is a 223 cc , and comparatively low compression bike.

Probably that may be the reason. Even after tunning the bike in most rich setting, the spark plug is still ......... very very light brown, almost white. Where as in my HH Hunk'2010 (the previous one) I maintained the dark brown color of the spark plug - hope this setting helps you to enjoy your bike for a longer period of time - without engine re build.

The stock ZMA setting is an ideal one.. it is neither lean nor rich, and for a 223 cc returns good FE..if you want the plug to turn dark tan change main jet to 135.

How and where I can get the 135 main jet - any idea?

Just get an exhaust from Joel and forget other modifications. Leave gearing untouched as its 5th gear is quite overgeared. The important tips for good mileage to inculcate in your riding habits are:

1. Always try to remain in the top gear. However, if speeds lower, you should downshift too, to remain in mileage band, which is usually from 2500 rpm to 4000 rpm. For karizma it is around 2500 to 3000.

2. About accelerator, Some people have this habit of On-Off Accelerator style. They give some throttle, and then roll back some, then again give throttle.
Keep a required amount throttle and try moving it smoothly.

3. Avoid long idling unnecessarily at traffic signals, etc.

4. Keep correct air pressures. This is another big reason for bad mileage. Keep a little extra if possible... So, if manual says 25 and 32, you can keep 27 and 34 or so, not above it.
If you keep above +2 of air pressure, your tyres won't have grip or it may explode, injuring people around it.

5. Keeping Bike in sunlight evaporates its petrol rapidly!! Avoid sunlight parking at all costs!

These tips may also help a lot:

1. Always warmup when starting the bike in morning. Warmup is necessary for oil to circulate the crankcase completely and smoothen running. 20 seconds or warmup is enough.

2. Adhere to its Service Schedule properly.

Believe me, any rider who keeps these in mind can gain almost 10-25% increase in mileage or maybe even more.
These all come from a guy getting 48 kmpl (!) on a Pulsar 180 (!!) with K&N and a bigger jet from Karizma's carburettor installed (!!!).

Thank you very much for all the inputs guys...

So, most of you suggest its better i change my driving habits than meddle with the engine...
I'm getting a mileage of 30kmpl in the city...Does filling the tyres with nitrogen help in anyway??
I'll also get the carb cleaned and air filter replaced (which i can never find here )

One doubt: I did a mileage test using 100ml bottle with my mechanic and got 51 kmpl..was shocked....why dont i get such figures overrall?? Does the petrol bunk guys cheat in anyway??