Alright here's a pic.It don't look like much but like i said it's for dry conditions and it works. I don't know if i would chop your only airbox cover to do it,i did because this quad is only for flattrack/tt racing.If anybody wants one made,I have a airbox on ebay and will split it up for $50.Of coarse it would look better than this one.
Everything's on the dyno sheet.The mixture screw was leaned a 1/2 turn and i leaned the low end a little.Air/fuel was 12.5 to 1.I have that graph also if you want to see it.
I did basically the same mod to mine,cut a hole in the air box behind the steeering stem in front of the gas tank.I took a piece of screen and screwed it over the hole and put a piece of foam over it and left the piece of plastic that covers that area off.It does make a difference.Gaged in a drag race and made about a quad length difference in about 600-700ft.It works for sure but ONLY use in dry conditions.
Thanks to your guys ideas I've modded a airbox lid. I actually found a filter that fits great. Its a perfect size for the lid. Its a briggs + stratton filter part#399877. I wish KN made a replacement filter. I'll try to get a few pics up soon. :usa
Have you guys checked to see if any of these filters would work? Why hasnt anyone came up with a custom like aluminum airbox yet? why not run two round k&n's up front under the plastic?
Haydug please tell me more about your setup and post pics if u dont mind. It would be nice to make a new airbox design that would work for all riding conditions and work with the 250R conversion.