Yes, sounds like you have too much "nose-up" thrust on the motor. With the Kangaroo, raising the aft of the motor produces nose-up thrust, so remove several of the washers under the back of the engine. I started with two washers and after I got comfortable with the plane, I reduced it to one.

Do note though that removing washers from the back of the plane increases the tendency for the engine thrust to force the nose down at low speeds and high power settings. This can be an issue in situations like go-arounds and power-on stalls. Beware the Kangroo "chicken-flop" and if it happens to you, decrease power to idle *immediately*, get the airplane flying again, and then add power as slowly as possible to fly out of it. It is a fun trick to do at altitude on purpose though...

Bob