One that externally vents crankcase rubbish.
Shape of the inlet runner track can have an effect too.
Hi All,
You have now given the motor more air than fuel, this causes a lean mixture that generally makes the bike run hotter. Leaner means better economy, less power hotter running , pinging and potential engine damage
I'd actually checked with my local harley dealer where the bike came from and they said it really wouldn't make any difference, it woukd be fine. It's been tuned with a SE Pro tuner for stage one already. Obviously it's a bigger difference between the stock air filter upgrade kit and a proper air filter upgrade.
Hi Krash,