The new one that I am trying to use is keeping my driveshaft from going all the way into the propeller. Resulting effect is that it is pushing my engine bed plate a 1/4 inch towards the nose. I can't line my holes on the engine plat up with the center of my rubber engine mounts. I believe that the O ring is the wrong size. That it is to big. I already hit the coupler pretty hard with a rubber mallet. I don't want to force it and break something . Are the rubber o rings standard size on driveshafts ? Anybody know how to fix this problem ?