How to change oil in zx10r - 2006 kawasaki ZX-10R

Check for foreign items in the air intake. Leaves, label off air filter, old registration....if it sounds like paper, it's probably something in there affecting airflow

The average MPG is in the mid to high 30's, but is also very dependent on your right wrist.

if it has carbie/s then check for a faulty float needle and seat
may be a simple thing such as a hair stuck under the needle as it is flooding

I bought a 04 zx10r. good battery but no electrical power any where but the starter relay. all of the suspected componets were chect on a running bike and perfermed normal. the issue was in the wire harness. I found a short in the #1 terminal connector on the left rail of the seat frame. It is hard to find as it is wraped in black tape. I found that the wire terminal had corroded and broken into. This wire leads back to the positive side of the starter relay and from that point it powers almost everything on the bike. I hope this helps. Good luck. Gixxerboy.

on most models you can follow the positive cable and there will be a black box not to far from the battery there should be a fuse in there if that fuse is blown you wont get power anywhere

As long as you get a muffler that is comparable to a stock muffler then it will have no effect on the performance. Most aftermarket companies make stock mufflers that would fit your bike though it would likely be cheaper to just replace them with stock kawasaki pipes.
As to replacing them, using an impact wrench will make removal easier and be sure to use a new clamp even if the old one looks good

http://www.superstreetbike.com/how_to_installation/0904_sbkp_2009_kawasaki_zx10r/photo_15.html

sound to me like the timing chain is in need of a tightening id get it in for a service if you havent already had one 6000mles it will be due anyway

did ypu change the plugs yourself

The frame mounting points are completely different. A zx 636 frame wraps around the motor where as a zx10r frame goes directly over the motor. That's how they keep the zx10r nimble enough to feel like a 600cc sport bike. But in this day and age if you have enough time and money you can accomplish anything. Honestly it's just easier to sell your 6 and buy a 1 liter.