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Discussion Starter #1
Hey guys Ive heard a lot of mixed reviews from different ppl, I would like to get some opinions of you guys. Here it goes.

If you change from o.e.m filter to a uni filter is jetting required? If you mode your exhaust with a uni filter is jetting required?? Guess an easier question would be is when is jetting actually required?

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I'm not sure exactly how much those mods would effect your SP500, as some machines are more temperamental than others, but usually the more air in= more out which requires more fuel to prevent a lean condition. Check your sprk plug. A spot on jetted machines plug should be a coffee brown. Too rich, the plug will be wet or even fouled. Too lean and the plug will be a white/ashy color.
 

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160 main with the exhaust and uni mod. Also needle adjustment depending on your elevation

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Discussion Starter #4
I live just south of ottawa so all my riding is done 0-2000m (0-6000ft) unless I go up moutians in Quebec.
So according to our service manual I currently have a 150 jet from the factory??

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150-155 depending on who set it up. The exhaust mod really doesn't need the jet increase but most 500s I have came across run lean. The uni mod is only worth it if your airbox snorkel has been updated or you install 1" uni filter air box vents.

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Discussion Starter #6
150-155 depending on who set it up. The exhaust mod really doesn't need the jet increase but most 500s I have came across run lean. The uni mod is only worth it if your airbox snorkel has been updated or you install 1" uni filter air box vents.

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Sorry you lost me with the last sentence! ! Lol. So your saying unless I snorkel my machine there is no need to stray away from the oem filter??

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The unifilter will flow more air than the air box can handle. To get the best performance from the airbox search for uni filter airbox vents. Install 4 of them in the top of airbox lid. Then go ahead and jet up

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Discussion Starter #9
What size and do I need to cut holes in the air box lid to install them? And are they water tight cause I have a habit of plaing in lots of mud and water lol

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I have a habit of plaing in lots of mud and water lol

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Those vents are not for you then. The best thing about the UNI is not the air flow, but the protection it gives your engine over the stock paper filter. A properly oiled foam filter can not be beat for filtration. The flow of an air filter on an ATV is not something to consider. All filters available will flow WAY more than your engine is going to use. The filter is all about protection and its not going to affect HP enough to worry about.
 

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Discussion Starter #11
I have a habit of plaing in lots of mud and water lol

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Those vents are not for you then. The best thing about the UNI is not the air flow, but the protection it gives your engine over the stock paper filter. A properly oiled foam filter can not be beat for filtration. The flow of an air filter on an ATV is not something to consider. All filters available will flow WAY more than your engine is going to use. The filter is all about protection and its not going to affect HP enough to worry about.

I not actually looking so much for a whole bunch of h.p but just a tiny bit more response and wasnt sure if i wanted to jet the machine. I have just heard from ppl that if you use a uni filter you would have to jet and if you use a k&n you dont have too.
 
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