Trying to improve performance in an engine is not like adding new wheel covers to an old car to improve its looks. You need to step back and see the engine as a system where changes in one part drastically affect another. Adding exhaust, using needle shims, changing needle clip position, cutting the slide spring, using K&N filters, or shoving in bigger jets without having a knowledgeable expectation of the outcome based on either known performance data or quantifiable result testing, is like cooking blindfolded with boxing gloves, who the hell knows what will happen. Fortunately there are low cost kits out there that have been quantifiably tested and proven to achieve results. But that doesn’t stop some from groping.
Don’t get wrong, All of us will always be guilty of guess work to some degree in our lives, but learning to minimize the use of guess work in all areas of our lives can only make us more effective, and having someone remind you of it is not a reprimand as much as an acknowledgment of the truth. Whether a person is willing, ready or able to accept the truth as an inspirational epiphany rather then a challenge to authority is a matter of character.