When you rock the prop tips back and forth on compression, you should get about 1 1/6" play back and forth..when the engine is hot you may get about 1/8" but as the engine cools it should go back to about 1 1/16"...

When the wrist pin started going on my first one you could hear a high-pitched metallic ringing in the air and on the ground..my second one hasnt had any problems but it came with all the updated parts.