i just bought a hmf slip-on for my z400. the modification that ive managed to find and dig up say to increase the main jet to a 170 and to remove the snorkle from the air box. If I was to get the full system it says to increase to a 175 main jet size and also remove the snorkle as well as drill 3 to 5 one inch holes in the lid of the box. I was wondering if this sounds right or is there any other method some of you guys used that might of pepped the z up a little more. thanx

check with hmf

i did check with hmf, i was just wondering if there were any other little trix or secrets to squeeze out a little more hp than what they prescribed

oh and thanx for the imput, duh

I got the slip on for my Z. First i took off the snorkle, but at the dunes it wasnt enough.So I just took off the airbox lid and bought the 170 main jet from hmf for $5

i plan on gettin the jet, but i was kinda wondering about drilling holes in the lid instead of taking it off, and wasnt you worried about sand crawling up and through the airbox, or are you running a k and n with a pre filter

no im using a UNI, but i bought one of those outerwears air box covers

Get a jig-saw and cut the airbox off around the boot to the filer. Get an outerwear for it and run it like that. A suggestion for those that dont go through water lol.

thanx for the info, but i do way to much creek rindin to do that