Yes, tighten down #3. I like to use two 1/2" wrench to tighten #3 AGAINST #4. That's how the #4 jam nut works to prevent the prop from throwing in the event of a backfire. As mentioned above, shorten the cone attachment bolt. You can estimate how much to cut off by estimating the free play between the cone and bolt. Do not overtighten the bolt against the cone and this might deform the cone. I like to apply a drop of blue loctite on the tip of the bolt.