Query Approved.

Try locating a company owned/retail outlet, on most occasions they are fair.

Do you carry a pillion of different dimension on/off?
Do you ride on rough roads?
Do you accelerate/brake hard?

The chain shall need lubing adjusting every 500kms, but depends entirely on terrain(smooth tarmac=less/harsh tarmac=more frequent)

Have you noticed Air-planes being given a shower? It reduces drag & improves efficeincy.

I think your carb needs proper tuning, head to a good mechanic and keep an eye on tire-pressure, they are determinal for the efficiency.

you need to first check the condition of your spark plug, to understand whether you are running rich in the a/f mixture, or something is wrong with the bike, which is putting a strain on the bike.

Can you find out from the RC book for us pls?

Fine; what're the other problems apart from low mileage & loose chain?

Can you measure using the ODO for us pls?

Well it depends upon how you come to 4th; you can rev on 1st, 2nd, 3rd & come to 4th to ride normally, or come to 4th & ride in 60+. But I hope you're not doing any of these & you're shifting the gears according to recommended on the speedo & riding well within the green limits. Also it depends on how you ride in traffic. But anyway, even if brakes are used heavy in traffic, the mileage should still be in the range of 55+ Kmpl.

This means the puller assy of the motorcycle has gone kaput. What you need to be doing is...
1. If you're a DIY guy, get a chain puller assy from the H.H.A.S.S & replace it by yourself
2. If you're not a DIY guy, take it to H.H.A.S.S & ask them to check why the chain gets loosened often & go according to their recommendation. Its most probably with the chain puller assy.
Note that the replacement of puller assy is based on the assumption that you're motorcycle is more than half decade old. If not let us know.

Depends on the usage; usually check for every 2-3K kms

Very true

Cleaning in what way? Polishing & water wash will not help with mileage. But cleaning inside the vehicle such as lubing & cleaning the required parts WILL attribute to improving the mileage.

Go about in this order...
1. Check the carbs for crack or damaged jets, tuned according to H.H specification, clean the carbs thoroughly (since you rarely clean)
2. Clean the airfilter
3. Check the wheel bearings for necessary lubrication & for any bends & do truing if necessary
4. Check your throttle wire checked & replace if necessary
5. Check your clutch plates, friction plates & cable & lube or replace them if necessary
6. Last but not least, get your ODO, speedo & fuel guage meters checked

Note - You can choose to do all the above by yourself, or, take it to nearest H.H.A.S.S & tell them your issues & you'll get all the things sorted.

Keep us posted on the updates

Keep changing ur engine oil regularly. as already told by someone, get ur carb cleaned and tuned, clutch plates checked.

and always, maintain tire pressure.