As with larger Bobcat / Falcon type planes, this one has the same quirks as the larger plane.

The problem is that the plane sits somewhat level on the ground.

The rear mounted prop, tends to push the nose down at runup.

This causes the plane to have a negative angle of attack, which in turn means it will run and run and run w/o lifting off.

If it does achieve enough speed, it will then shoot up like a rocket, though usually it may not.

What you need to do is to adjust the gear so that the plane sits nose higher than the tail, giving the wings a positive AOA.