This is a very good point. Without the air filter on, the sound of the engine sucking the air/fuel mix into the combustion chamber is amplified, which may make it sound a lot noisier than it really is. I will say, I envy that setup with the filter mounted above the carb! Would make getting to it on my 110 a lot easier.I wonder if it would sound better to you with the air cleaner and filter in place? Sounds pretty good to me as is but sometimes we are not hearing what you are exactly. Nice work.