I'm looking for some more low end power with my z-400 so i think im gonna get a K&N filter. I was also gonna get the outerwears prefilter and the air box cover made by outerwears thats waterproof...but still sucks in air....I was wondering if that cover is better than running the airbox lid with the 6 holes and the little pop-in vents.

Also, once i do the mods, i was wondering what size jet i was going to need to go to, and if i would need to change any needle positions or anything

Thanks
Tony

 

i have hmf slipon and white bros power filter 165 main jet stock needle two 2inch holes in lid .works great.