The Saito 72 should be a perfect match for your plane. You will find that you may want to allow a longer takeoff run with the heavier engine to permit gaining flight speed. What you encountered was a departure stall caused by insufficient flight speed at the time of takeoff.

In the future, should your plane leave the ground prior to gaining what you believe to be adaquate flight speed, keep the plane low and level, within 1/2 wingspan of the ground, and gain more airspeed. This will keep you in what is known as "ground effect". This is a condition where there is a "cushion" of air under the wing caused by the compression of the air by the lifting wing.