So In installed my EPI sport/utility clutch kit on my 02 Sportsman 700 and when you go move it engages very abruptly and makes a clunk noise. Is this normal for the EPI kit. The primary spring (orange) was like an inch longer than the one that came out (white). Its like the wieghts are sticking or something as when I apply throttle the primary shieve doesn't move at all then all of a sudden it jumps out and engages very quickly.

 

With some clutch kits you may notice a slightly higher rpm engagement and or a more abrupt. The quicker engagement can be a good thing when it comes to your belt and putting power to the ground. (more positive engagement and less slipping on take off) As for the clunck????

 

EPI chad where are you??

 

The Epi Orange spring is rated at an engagement of 75 with a shiftout of 140 and the Polaris White spring is rated at an engagement of 34 with a shiftout of 140.Do you know the numbers on the EPI weights and the numbers on your factory weights?

With the information that I know about the primary springs it looks like there is a huge difference in the stall speed and the shiftout is the same, but the weights may change that depending on their size.Going from a stall speed rating of 34 to a rating of 75 is big difference.That would raise your launch RPM's quite a bit and probably take some getting used to.

Did you change your secondary clutch spring?If you did did you rotate the helix 1/3 of a turn before you pushed it down and locked it into place between the buttons with the snap ring?The reason that I ask is because I've seen people not rotate the helix and lock it down and have heard it make a popping sound.That will also effect how the quad runs also.

 

sounds right,about the secondary,,,,,,,,,,check the primary also,if you put the white back in and its fine,,,,,,,the tighter spring is aggrevateing the clearance,,,,,,,,,

 

This is an 02 700 with EBS, it has rollers not buttons and EPI support told me not to do the 1/3 rotation thing due to different helix design. I will have to pull it apart again this Friday or Saturday and look at the weight size. Its a dark blue secondary spring.

The funny thing as I ease the gas on slowly but when the clutch sheave finally moves it moves immediatly, not gradually.

 

I wasn't sure when Polaris switched to the roller secondary's, sorry about telling you to do the 1/3 turn on your secondary.On the upside the roller secondary is a better design IMO.I actually switched to a Team Roller Secondary in my 99 Sport that I dragrace this year because of the better reliablity of it over the teflon coated button design of the older design Polaris secondary's.

Not trying to second guess EPI, because I really feel that they make a good product and are one of the better vendor's in our hobby, but you might be happier with a lower engagement speed.I'm sure that with the money you just spent on the clutch kit you probably don't want to spend anymore, but you might be happier with a primary spring with a lower engagement like the EPI dark green primary spring.According to the EPI website it has an engagement and shiftout of 55-145 compared to the orange primary that you have of 75-140.

The 55 engagement of the EPI dark green compared to the 75 of the orange EPI should engage quite a bit earlier in the RPM range, but still give you a higer engagement than the factory Polaris white primary springs 34 engagement RPM.If you have a tach you can compare your factory engagement RPM to your engagement RPM that you have now.

The only downside that I might see with the EPI dark green is that it has a higher shiftout at 145 compared to the factory white primary and EPI orange primary of 140.This means that your clutch will shiftout at a higher RPM which it may not need to.The difference should be very slight and you might not be able to really tell a difference unless your on a dragstrip with timers or a dyno.

A few examples on clutching that I can give you are with the Sport that I dragrace on my local IHRA paved 1/8th mile mile dragstrip.When I switched from a primary with an engagement of 101 to a primary with an engagement of 120 my 60' times dropped from 1.94 to 1.87 consistently, but it made a huge difference in my stall speed.I wouldn't recommend such a high stall for anything other than racing just because it wouldn't be much fun on a trail and when it engages it engages hard.

When I changed my shiftout from a 269 to a 260 I went from running 8.60's in the 1/8th mile to running 8.50's in the 1/8th mile.Part of that might be from my better 60' time that I mentioned before, but I feel like the motor operated better at a slightly lower shiftout RPM that I was currently running.Before that I tried two different primary springs with shiftouts of 290 and 300 and was running 8.80's in the 1/8th mile with both of them.Depending on what RPM your motor operates best at and your tire size and gearing (if you're running a chain and sprockets) less might be better sometimes.

One thing that I noticed with the higer shiftouts was that before I got to the end of the 1/8th mile track it would feel like my Sport was topped out and just wouldn't go any faster.My mph on those runs confirmed that by picking up 2-3 more mph with the 260 and 269 shiftout springs as opposed to the 290 and 300 shiftout springs.

 

Thanks for your help on this. I am still going to take it apart and verify the smooth operation of the primary and will post an update. I did order the EPI dark Green primary spring so i can play around. I only paid $61 for the whole clutch kit brand new on Ebay which included the primary spring and weights, secondary spring and helix, I thought I got a good deal.

 

Sorry I missed this yesterday, I've been doing a lot of testing on the new Commander and not in the office as much later. Yes the Dark Green spring should lower the engagement compared to the orange. Normally the top rpms and feel stay the same as the orange just a lower initial engagement.

I believe we talked on the phone this morning but if you run into any other issues just give us a call.

 

Oh, that was you Chad, thanks for the help, sorry I had two calls going at one time. I will pull the cover off the primary and check the bushing, and post my results. What is the engagement RPM of that orange spring and weights in WE415030 kit? It feels like 3000rpms or so, by my butt tach. That seem real aggressive for a sport/trail kit.