I have a 98 400l sport with a K&N air filter, A HPD clutch kit and a HPD performance exhaust. i was wondering what the next step i should take to make my quad a little quicker off of the starts and maybe even a quicker top end. should i get maybe get some after market reeds or a bigger piston. any and all suggestions are appreciated.

 

The next logical thing would be to add a carb, either 38TMX or 39PWK, and have some port work done to the cylinder, by either HPD or Ritter.

 

Put in a Wiseco piston and Delta V-Force reeds.

 

Buck,

Welcome to the wonderful world of modified Polaris ATVs. There are so many ways to modify it, the possibilities are endless. Like Jerry said, a new carb would be in order along with reeds and a cage. The next logical step after that would be porting and head mods. The suspension work comes after that. Click on the link below my name to visit my site. You'll find that I've listed on page 3 all of the mods I've made to mine. That is a good place to start.

I don't think a big bore kit will give you much more in terms of usable horsepower. Get it ported, do the head mods,get a larger carb and better reeds. You'll be happy, like me.

Oh yeah, DON'T forget the Wiseco piston!

 

The V Force Delta 2 Reeds are about the best out there right now. I put a set on with a reed cage spacer ( get the HPD one, about $22.95 w/ Gaskets & new bolts ) and had pretty good seat-of-the-pants improvement. I have not tried a different carb yet, but when the cylinder & Head get back, I'm sure that I'll be looking for more intake airflow. Ask Mike about the UFO and possibly getting the carb bored larger.

 

I also have the hpd pipe and clutch kit,I used to think that made a huge difference in the quads performance,but after that I installed a wiseco piston,v-force reeds,hpd porting,hpd billet head,kehin 39mm carb,and now let me tell you that made a DIFFERANCE....only thing is I did all my mods at the same time so I dont know which one made the most improvment so bust out that visa and go for it
http://msnhomepages.talkcity.com/RightWay/hiperfpolaris

99 sport 400
hpd pipe
hpd muffler
hpd porting
hpd billet head
hpd girdle kit
39mm kehin pwk carb
renthal cr low bend bars
wiseco piston
hpd aggresive clutch kit
v-force reeds
k&n filter


2000 scrambler 400 2x4
prm alum. a-arm gaurds
renthal cr low bend bars
dg alum. bumper
k&n filter

 

i appreciate all of the information that you guys have gave me. i think that i am going to get some new reeds and a weisco piston. but if i get the piston should i have it bored also while its all apart or no. how much des it cost to get it bored? i do not need an exact price just a ballpark figure. but for now because im going to ride next weekend im going to throw some new reeds in there and when i get back ill put a piston in there. thanks for all of the information that you guys gave me

 

A wiesco piston should cost between $90 and $95.
Have the cylinder bored and honed $30 to $40. Put in new gaskets and coolant and you're ready to ride. Check the coolant hoses while it's apart, their easier to change.