Am I hurting or gaining anything when I take the air box cover off of my 300ex? I know not to get mud or water in it and I know it makes it realy loud.

 

Running with the lid off provides maximum air flow through the filter. You'll have to increase jetting to match the increase in air you gained by removing the lid. A vented air lid is another option. Both are good mods.

 

What do I need to increase

 

A bigger main jet, to be had from your local dealer. I'm running a 130, stock was 122.

 

With the Supertrapp pipe, you're probably running lean right now with a stock main jet. Removing the lid will increase that problem even more, so I would pick up at least two main jets, each one a size fatter that you stock one. Install the bigger one first & test ride, read the plug, and go from there as to whether you need to drop a size. Do it NOW before you do any damage to valves or other components.
If you need info on plug reading you can email me.
I've put it on here a dozen times or more..people are sick of it.

 

i wont tell u what to do, but this is what i wanna do. i want to get an aftermarket airbox or another lid, drill holes in 1 and run it like that, then switch it up when im in water.