Has anybody done any successful mods to a sportsman air box. I think there is a lot of room for flow improvement here. Please let me know and what jetting changes were made. I'm waking up a 1997 Sportsman 500. I currently run a 135 jet in the stock carb at 5-6000 ft for most riding. Thought about a K&N that clamps directly to the carb but I need a little more water protection. Thanks for any help.

 

Just buy 8-10 1" vents for your airbox lid. It greatly improves your engines ability to breath with a decent filter and pipe. You oil them so they will bead a little water off. Keep in mind you'd have to pay more attention to those water crossings because a snorkle end is usually located higher than the top of the airbox.

Also, a 1" wood bit works great on the soft plastic. They stick pretty good, but I'd add a drop of glue on the inside of the lid on each vent rim to keep it from vibrating loose. Watch the jetting. More airflow requires a larger jet.

Good luck!

 

THe CV carb on these need a certan amount of vacum to operate correctly so you may need to give HPD a call.They make a airbox mod for the 500 Scrambler and may have something for the Sportsman.

 

Huh? ftwflh, I think somebody's been yanking your chain if they told you vents would be detrimental to carb performance.

 

As I sated CV carbs will not work properly with out the right amount of vacume! You cant even get a Polaris 4stroke to run right with the air box lid off. Post this thread in the Polaris forum and find out.Now on the Polaris 2stokes opening up the airbox helps alot.But these are 2 totally diferant carbs.

 

Thanks ftwflh that was my biggest concern. I may be ignorant but who is HPD

 

Here is thier link http://www.hpd-inc.com Give them a call Darrl will give you the lowdown on what you need. Hey stop in the Polaris forum in here and get aquainted with the rest of us Polaris riders.

 

Whatever, I think it must be jetting or something else but believe it needs a vacuum if you want.

ps - Say Mikuni or use some other excuse because I have a cv carb.

 

Been there, done that. And ended up with the HPD air box mod. The 500 will run like crap if you start messing with the airbox. And you have to do more that just re-jet, you actually have to recalibrate the carb. My HPD kit came with a new slide spring, main jet, and needle jet tube, as well as a massive air scoop. The CV carbs DO require vaccum to work properly. Messing with the vaccum in the airbox that the carb was designed to run with by opening it up requires more adjustments to make it work right. And yes, these are Mikuni carbs

 

Thanks for all the help and the link. I will check it out when they are open.