90 Hp Crossflow , Removing the engine cover gains 1.5 mph ??

[Faztbullet]

No that's the way its jetted from factory. If you pulled the black silencer cover off @ WOT on a dyno you would see a fog vapor in front of carb throat. The reason is when the reed valve closes shut a reversion pulse is reflected back through the intake flow. This pulse pushes back the charge the wrong way out the throat of the carburetor.This is why if you take air cover off it has a washed area in plastic.Do not run with aircover removed as its will lean out and a fire hazard as i twill impregnate foam in front of carbs with fuel.There a lot to airboxes restrictive and non restrictive but wont go into that...

 

[StingRay_90V4]

I have not removed my front intake cover. And I will definitely plan on keeping it installed. Catching on fire is not cool for sure. What about if I leave the intake cover on of course. And pick up a second engine cowl. And cut holes in it in a few places to allow more cooler air in like when tje cowl is off. Is there any damage that can be caused to the engine by giving it cooler air to make it lean oit and go that far bit faster ? If it works by cutting apart an old cowl and won't hurt my engineby going too far lean then I'm all for it.

 

[Faztbullet]

Don't butcher a cowl and allow water intrusion...order 432829 and 432828 cowl vents and install.