Hahaha. Defrauding the government. What a company.

https://www.chuckhawks.com/harley_tax.htm

https://www.v-twinforum.com/forums/harley-davidson-sportster/4022-what-harley-tax.html

https://harleydavidsonmaintenance.com/maintenance/paying-the-harley-tax/

There is a basic truth about internal combustion engines; they need to breath! Restrictions to the intake and exhaust system keep engines from reaching their power output potential. Out of the box, a Harley Davidson motorcycle is ‘dumbed down’ to meet federal and or state emissions guidelines. Fuel systems run lean, air cleaners are restrictive, and exhaust systems act like a clogged drain on the entire engine. Fortunately there are factory and aftermarket parts for your motorcycle to help you beat the tax man. They can be installed separately for smaller performance improvements, or together for optimal power increase. Whichever way your budget allows you to approach paying the Harley Tax, have a plan for what the final improvements will be and how the parts will work together.

So yea, about that.