I have purchase a new pulsar bike in 2015,october. and also 1st free service was done in 600 km. now i reached 3425 km. i am having problem .. oil leak in engine head. what happen ?

Hello. Please request assistance ASAP with vendor. You should have warranty.

Oil change intervals for motorcycles depend a great deal on your riding conditions and riding style. For lower-revving street bikes, I often change my oil about every 2000 miles (~3200 km). However, someone with a sport bike who regularly revs their engine closer to the redline, I would suggest a more frequent change interval. Off-road / dirt bikes should have their oil changed sooner because of the dusty conditions. The oil is still full of lubricants, but it is contaminated with dust and dirt that clogs the filter and eventually goes right into the engine, increasing wear. I can't offer much guidance for dirt bike oil change intervals.

check your spark plug and see what color it is, it sounds like you might be running really lean and that will cause the bike to run hot. if the plug is white or lighter in color thats most likely what is happing.

http://en.wikipedia.org/wiki/Bajaj_Pulsar is a good source of information on that bike.
or here http://indiareviews.wordpress.com/2006/08/17/p-180-dtsi-long-term-review/

I dont think so.If the bike has done 16000kms then it is possible that the tyres are finished with the best part. If you are having 40 grands to spend for an old bike, it iis much bettter to go for a new bike,Give a downpayment of 20000 with the rest on an easy loan instalment scheme , you will money with you for the next 10 instalments but still have a trouble free new bike for al least three years, so the saving on your service will stand good later and the resale when you can sell a first owner bike. So think and decide. Good day

you mean to say that you want to service the bike by yourself
1st of all see when was the bike last service at how much Km.
if it was long time then 1st of all better replace Engine Oil & Oil Filter better go through Instruction manual for better understanding of your bike Engine it's working & every dimension for a hazard free trouble free ride just visit your nearest authorized service station.

I have been using Castrol Active (Grade - 20 W 40) in this bike and have never faced any problems. Do not use the Castrol Power 1. Also get the engine oil changed after every 2500 kms. (get it replaced after 500 - 600 kms during the 1st service and after that change every 2500 kms)

Actually I too had the same problem when i bought the new pulsar in 2007 dec, For the first 4 months i struggled a lot because of this low pick up problem, I had given my bike for the Show room services 3 times in 4 months,Every time they will be Tighthing the cluth & applying greece over the grooves, but it does'nt worked up & my bike was reaching only 80 km(maximum) after giving the high throttle for long time... and the mileage would be 23 Km,,,But i went for the service out side the company few guys told it would be the Piston shaft problem,, few guys asked me to change the Clutch plate,,, One Mechanic Just lubricated my clutck plates(serviced it Just released the jam Clutch plates) Now 1 and half year gone it is giving the Mileage of 52 Kms,And the maximum speed 113(which I had tried).....Going smoothly....

pink oil? i dont think so. sounds like your clutch is slipping
http://www.carlsalter.com/motorcycle-manuals.asp i think you can find a free service manual here