Please keep informed, My stepdad is looking to put a pipe and clutch kit on his 500..His 400 responded well to a Hpd pipe,silencer and clutch kit. Also Ritter airbox mod kit..

 

Guys, I have tried it all with my '03 Scrammy 500HO. Listen, dont waste your money on a clutch kit. You will lose all bottom end torque and jump off the line. The stock clutch is the best for a 4-stroke polaris. Your 4-stroke power is huge on the bottom end. It is the 2-strokes that need to get up higher in the RPM range to reach there power off the line. Here i will give you my cheap and easy secrets togo big with your scrammy. First off White Bros. E-series pipe! Second an airbox mod with re-jetting. Cut a 2inch by 3 inch hole right behind the snorkel tube. velcro on an outerwares pre filter to keep out dirt and water. Next you need a stage 2 jet kit. No body offers one yet! I worked with an engineer from Dynojet and would not take no for an answer!!! You need to use a stage 1 kit for a Polaris Magnum 425 '98. Put the air needle in with c-clip on the third notch 160 main jet and turn the fuel mixture screw in all the way and then out 4 full turns. You will have to drill out a 5/32 brass plug to get to the screw on the bottom of the carb. These are cheap easy mods to gain 9 1/2 hp on the Dyno. I all ready spent the money on the Dyno for you guys! I can beat mildly modified z400 and 400ex quads in a 3 hundred foot drag race by 1 and 2 bike lengths respectively. Lets not even talk about on the trails!!! This set-up is for 3000 feet in elevation or less using a Uni-filter. Happy riding and tell us how awesome your Scrammy is now!!!

 

What kind of clutch kit did you get? Rick set me up with a lower engagement HPD kit for trails. The HPD pipe comes with I believe a 165 main jet. Would I need anything else for the airbox mod besides the 165 jet? Would 165 be right with a pipe, K&N, and air box mod? Can I use the prefilter that came on my stock filter instead of buying another outwears? Thanks for the ideas. [img]i/expressions/face-icon-small-happy.gif[/img]

 

Trialking.

Did you get only the slip on silencer or full exhaust? Wouldn't there be a beter chance of getting water in the airbox if you mod it even if you put something over the holes?

 

There would be a better chance of getting water in the air box, but that is what the water-proof outerwear is for on the air filter.

 

Here are some good links to check out about the airbox mods:

http://forums.atvconnection.com/mess...eyword1=airbox

http://forums.atvconnection.com/mess...eyword1=airbox

 

Dont worry about water in the air box as long as you use an outerwares pre-filter. They do make a water proof version that costs one dollar more. I tried some bench testing with the stock pre filter and found that it would hold up to water spray but would not hold up to a full immersion, it will let water pass through. I have yet to get water in the air box with the outerwares pre-filter, and i do get in deep for fun!!! As for the e-series exhaust all I am aware White Bros. offers is a slip on at this time. I only found one header pipe in the aftermarket and it was made by DG. I did not purchase it because the Polaris super header used on the Scrambler is a very smooth and well designed piece. I dont feel it would be a performance gain to use an aftermarket header pipe, only cosmetic. I think a 165 main jet when used in conjuction with a K & N filter and better flowing exhaust would be worth looking at. I have not used this set-up since I am not a big fan of using a paper filter in any off road application including my dirt bike. Foam is the only reliable way to achieve max air flow. Paper air filters become to restrictive very quickly when subjected to dusty enviroments. I can tell you that with my Scrammy the 160 main jet has been very potent with the needle I am using. You can change jettng all day, but to gain power from bottom to top you must use the correct needle. For instance I tried the stock needle with a 160 jet and air box mod but gained no significant power increase. Kind of defeats the purpose. I am a little rich on the bottom end, but lean out perfect at higher rpm. Leaning out at higher rpm is where you can lose most of your power. You need balance on both bottom and top. After a month of testing I finally found the happy middle ground. I did not use the hpd agressive low engagement clutch. I will have to look into that. I just dont see how it can improve on the stock setup. I have never suffered belt slip and hook up like no other!!! You know Polaris uses the same clutch in snowmobiles that are around 90hp. Im not quite there yet! I appreciate everybodys input and hope somebody can give me some good performance ideas! Remember, safety gear not only helps keep you in one piece, but it looks cool too!

 

I'm lost. If you install a clutch kit, you are not changing the whole clutch itself. All you get it a different helix, weights, springs, and shims. They are not a replacement for a clutch, just an improvement. Are you talking about something else?

I was always told that anytime you modify exhaust or intake (carb/air box), for the best response, you must change the clutch engagement to match the RPM change. Why would you not want to modify your clutch?

In my spring/summer Rocky Mtn. ATV catalog, they list the Supertrap complete I.D.S. system with header pipe for $189. Don't know if that's an error or not though. Sounds pretty cheap.

 

I have to apologize fo using such vague terms regarding the different clutch kits available. The centrifuge clutch assy mounted on the crank is the drive clutch and the assy on the transmission is the driven clutch. I have done a lot of work with the local bike shop and have found that with the four stroke engines you do not need to alter your engagement point of the clutch unless your engine does not "come on" until a different RPM whether it be higher or lower. The 500HO starts to generate its best power right where the factory clutch engages. The only way I can see a clutch kit being a benefit to me is maybe letting the transmission upshift later in the rpms. I will get back to you on the exact kit I had installed so maybe to keep someone from making that mistake. It is good to see more companies offering quality exaust if you are indeed correct.

 

So Do I need to raise the needle or get a jet kit. Like I said, the HPD pipe comes with a 165 jet but I think that it says to raise the needle.? (Someone help me out here). I usually dont get into deep water, just a little bit of mud now and then. Most of my riding is in dry conditions because my friends are scared of the mud with the DS and dirt bikes[img]i/expressions/face-icon-small-happy.gif[/img] Do you think that the stock prefilter would work in my case. I have an outwears on my K&N as well. How much more should I raise the needle with the 165 jet? Do you have any pictures of your airbox mod? Thanks trailking47711