Hello guys,
     Iam interested in buying a tachometer for low price.I want to use it for motors,which are used for multi-rotors. If anyone interested in selling their tachometer please reply to this message.

Usually you don't require a tachometer for motors Cause its RPM is already specified on most motors...
Which motors are you using ?

@rahul quady,

1. Do you really need a tach? 90% of the time we can manage without one.
2. Usually you'd need one to check the rpm a given motor can produce with different props
3. Or if you are just interested to know the rpm.
4. If you get one, remember to use it in bright sunlight. Not indoors with tubelights, where it will show 300! (Ie, 3000rpm). Interesting to figure out why.

Have fun when you get one. I got one not because i really needed it, but because i always wanted one!
Regards.

Available at rcmumbai.com

Iam using emax 2213 935kv motors for my quadcopter,and because a faulty esc, I lost all of my four motors,some kind of smoke came out from the motors,as soon as I connected the faulty esc to my lipo.One of my motor is completely damaged,it could'nt move properly.I think both coil and ballbearings were damaged.I don't know about other three motors,so I want to check their rpm.

Why dont tou just check the thrust of the motors ? And if the motors are not making any kind of weird sound and smell they should be ok .

Some kind of smoke was released  from  coils I think.Some of them smell differently,and I couldn't rotate one of the motors.So I removed the clip to see ball bearings,but I couldn't find any bearings,I JUST COULDN'T  UNDERSTAND ANYTHING! !PLEASE HELP!

photos will/would help

All the electric motors have same kind of smoke sealed in, and if you ever let them out they would just work no more.
As for the IC engines, each kind have different type of smoke, and need to let out the smoke to continue working.

On a serious note you do not need a tacho you need a watt meter.