Yes the bearing would only be worth doing if you go diesel to swing a big prop. I did think about the carb issue a while back and bought a carb rebuild kit. Notice the plastic ring to keep the screen on, without it the carb shows big improvement for performance could run without the pipe and file out the two drill holes to allow the engine to breath with some goo control leaving the muffler body on. Here's a pic. Note taper in the inside wall of the venturi. Note you save 14.6g thats tad over a half oz just removing the muffler pipe.