First we have to look at why the manufactures send you a jet with their exhaust in most instances. You just started pulling in more air with the filter and are evacuating more exhaust from the cylinder. This will cause the engine to run leaner. They give you a bigger jet to put more fuel into the cylinder so you dont burn a valve or piston. Of course you will have some gains in hp and torque. To achieve the most power you must change the needle!!! Dynojet explains this very well in their site www.dynojet.com. Why port the air box if your stock needle will not let more air in, or not the most possible? If the dealer doesn't rip you off the kit is @ 46 dollars. Dont go through the trouble of air box mods if you aren't going to put the better parts in the carb. As for the stock pre-filter, sound just perfect for you! Follow my instructions and I promise huge gains like me!!!

 

BigBadScrambler what elevation are you at the reason I ask is I have about the same mods as you and found that a 165 jet was too rich even though that is what they recommend (HPD) I found a 160 was plenty.

 

I ride in the middle of Michigan. I would say that it would be around 2000 ft a.s.l. You say that you have the same mods? How do you like the pipe (sound) and the overall package with the clutch kit? Do you have the same airbox mod as trailking47711? What exactly did you do with jetting? Just change the main jet and raise the needle? Do you have any pictures? Thanks a lot guys. You all have been a great help and given me a lot of good ideas to scrape any more hp that I can get out of the 500.

 

well I have the older style can(exhaust) but the same pipe I love the sound nice and deep at idle and a nice bark when punched. but not too loud I would expect the same from the newer can(exhaust) as for the clutch I run a HPDplain6 engage about 55 shiftout at 215 49 gram weights I did have 55 gram weights but found I lost some top RPM so I experimented and found 49 to be the best for me. and HPD violet secondary at 2 and 2 but was thinking of taking the clutch back to stock for comparison testing.
yes i do have and airbox mod like trailking I would listen to what he has to say since he spent time on the dyno I think he says to use the needle from a stage 1 kit from a 98 magnum 425 on the 3rd clip with the 160 mainjet

 

trailking47711,
Is there a way that I can buy just the needle for the Polaris Magnum 425 '98 instead of the whole jet kit? Because that is all that I will need right? The pipe comes with the 165 main jet. Do you think that I should switch to a 160 or keep the 165 and find a different needle? I would hate to but a $50 jet kit just to use the couple dollar needle. Does the dealer carry a needle for the stage 1 magnum kit. Ive also noticed that AAEN carrys mikuni carb needles. Is there a part number for that needle. Thanks for your help. Sorry if I am repeating myself but I am still trying to understand jetting and how to adjust it. I finally figured out how the clutch kit works!!![img]i/expressions/face-icon-small-happy.gif[/img] One thing a a time, ya know

 

I have to think Alpine2 for the great description of his clutching set-up. I will definately try yours as well as doing some of my own experimenting. I have been looking at dyno charts of the hpd pipe that BigBadScrambler is using. It is a little shy of the White Brothers E-series slip-on, but I dont think it is enough off to need a 165 jet. I have not tried it myself, but I do agree with Alpine2 160 does seem to be the magic number. Put the stock air needle out of your mind, it is not satisfactory. The Mikuni needles are stock only. Dynojet has their tech phone number on their site. Call and ask if the will sell you just the needle and 160 jet. Have them explain to you how their jets and needles are better than stock. They are very good, and have a lot of patience. BigBadScrambler I have done my homework on the jetting and have given you my notes. No where else are you going to spend @ 12 dollars per hp than my jet solution and air box mod!!! I will have some good clutch kit info by this sunday. I ride in so. Indiana, and we are less than 1000ft in altitude.

 

Thanks trailking47711, I will give Dynojet a call and see what they can do for me. BTW, did you velcro that outwears on the outside or inside of the air box lid?

 

What does anyone think of this, instead of cutting up the airbox??? Seems like a pretty steep price if you ask me. Why couldn't it just be made of plastic?

http://www.hotseatperformance.com/ps...=2261&CATID=82

 

I didn't even look at your link but figure you are talking about the billet air scoop. I thought about using it but I did not like the price! If you look on your stock snorkel you will probaly see a cut line on it that Polaris did not cut all the way to. I did and actually trimmed a little more off the bottom of the opening. That is the theory behind the billet scoop. Larger opening, smoother material? more air flow. It's not enough! The air box mod is safe, and looks pretty trick. If you try the HSP scoop tell us how you liked it.

 

I have a question for all you. Does anyone else have problems with the front inner wheel seals leaking? I have replaced both and wonder if you have found any thing better.




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'03 Scrammy 500HO
stock tires Titan 489
Hand fabricated twist throttle(motion pro twist assy.)
Hand fabricated shockwares
White Bros. E-series slip-on
Air box mod
Hand picked jetting parts
HSP nerf bars
Full armor (a must for our trail riding)
Re-valved rear shock (gotta soak up jumps somewhere)