Loss in current while voltage remains
So, there are a couple problems here:


You have a gain of 2.25 for your op amp, but your op-amp is powered by +9V and 0V:  you are trying to output 10V but you can't output more than about 7V.  The 7V comes from the fact that under load, your op amp can't actually output voltages at the "rails".  This parameter is under the "output voltage swing" in the datasheet, though I guessed that the 2V from the rails is consistent across voltages, which I'm not positive on.  You can confirm this by looking at what the voltage coming out of the op amp is in your circuit.  In general, it isn't a good idea to drive an op amp to the rails unless you have an op amp specifically designed for that (generally called rail-to-rail op amps).  Sometimes they can latch up (stick at the large voltage out), or they can go negative.
Your tip29 saturates at 0.7V, so when the transistor is , so best case scenario, you have 3.4V across your motor.  However, I think you aren't actually saturating it.  The Vce(sat) figure in the datasheet is 0.7V, at 1A collector current, and 125mA base current.  That means, if you want to saturate your transistor, you need to source 125mA of current into the base.  Your op amp datasheet says that the short circuit current that the op amp can deliver is 25mA.  Since you can't source enough current, the voltage across the transistor can't get as high as 3.4V.


Now, for the solutions:

The easy one is to replace the tip29 with a "logic level mosfet".  A mosfet can be considered a voltage controlled resistor.  When you change the voltage between the "gate" (analogous to the base of a transistor) and the "source" (analogous to the emitter of a transistor), the resistance between the source and the "collector" (analogous to the collector of a transistor) changes.  A large Vgs (voltage between gate and source) makes a small resistance. The important thing is that MOSFETs have a very high input resistance -- it doesn't really take any current at all to change the voltage of the gate.    Thus, your op amp won't have any trouble driving it.  The "logic level" part tells you that it is turned on by a voltage of around 3-5V.

How much current do you WANT to go through the motor?  This will help you decide on the mosfet to get.

tip29 datasheet: https://www.fairchildsemi.com/datasheets/ti/tip29.pdf

lm741 datasheet: http://www.ti.com/lit/ds/symlink/lm741.pdf