Aright I have a 1999 polaris sport 400 and I have heard that they need more aggresive clutch springs becaust the stock spring does not get all of the 400 cc 2 stroke power to the ground. I was wondering what color spring I need and what the numbers are on the spring and what other things I need like do I need a helix or somthing. I do mostly trail rideing and would like more mid to top end because my quad has good bottom end. I do not want to lose any bottom end tho. Could some one who knowes these quads please help me out thanks, rob

I also will need the spring rate number, I have read EPI pink (0-123-160) is good. This true. I want stock engagement

 

To get what you are wanting you will need a complete kit (both springs,differant weights and possibly a helix) The EPI pink is a good spring for the smaller 4strokes that just need a bit more rpms.You could try a yellow primary spring,Aaen blue or HPD violet secondary spring with a set of S58 shift weights This should get you what you are looking for.
If lowest engagment rpm is a big matter I would recomend a Dynoport pipe with a Polais green or Dalton black/ white primary spring with stock weights and one of the secondary springs I mentioned earlier.

 

what is the spring rate number on the yellow primary spring? I am looking for a spring that will not need helix or weights and just a bit more agressive spring that will make sure im geting all my power to the ground. I dont want to get into pipes and things.

 

It is 44-185 rate spring but it could get you out of the stock rpm range of the pipe.If you just want a good spring call Rick Ritter and get a Dalton Black/white.You can run that with stock set up.Set the secondary at 2-2.

 

ya id like to stay with everything stock and get just a bit more edge on the clutching and get all the power to the ground what is the rate on this Black/white. The reason i ask is i have a buddy with boxes of springs and he usualy can find me the spring if i have the rate number.

 

If going that route look for a spring in the 45-120 range.Polaris green is close but not quite as good.
But if you really want to blow away the comp find the Dynoport pipe and run a stock silencer.It builds more power without raising the rpm range.

 

aright 42 - 120 i will tell him and see what he comes up with i know he has a tun of AC things and snow runner clutches.