I set most all of our motors up at .003 clearance , if you had another builder tell you it wasnt bad enough to tear down im not sure how we know its bad enough to accuse me of boring it to "to big of bore". All motors if you take the head off and push on the piston it will rock back and forth as the top of the piston is much smaller in diameter than the skirt. Several times in this topic you stated it started making noise after 3 hours of riding , if it was piston slap normally they are loud right away and especially cold as when the motor heats up and piston expands they get quieter. Is it possible that the noise is your crank? Maybe a piston skirt collasped for some dumb reason who knows , things happen and i didnt assemble the motor. Anyway, what can i do to help?? If you want to send them back i will bore them at no charge and fire them right back out quickly IF NEEDED!!!!