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Discussion Starter #1
hey folks, I just purchased my predator last week and I love the power band that alot of people seam to hate, but being that I have owned numorous machines in the past I know it's only a matter of time before I feel the urge to mod. I talked to the dealer and he said that with the w/b slip on and the k&n drop in, no rejetting needs to be done unless your I believe 6 or 8 thousand ft above sea level. Is this right ? and have any of you done this and are pleased with the results? thanks
 

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I had the WB slipon pipe and the K&N drop in filter with the stock jetting and it ran great. I just recently modified the airbox to get more air flow and i had to go up from a 150 to a 162.5 main jet. I think you will be fine with stock jetting if you have not modified the air bock from stock configuration. Check you plug after you add your pipe and filter and ride for a little while. That will give you a good indication if its running good with the stock jetting.
 

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I would suggest going to at least a 152.5 or a 155 with the K&N and Pipe. With the stock pipe, there are no jetting recommendations. But if you contact K&N, they will tell you that with the filter and pipe, you need slight jetting adjustments. Remember, more air in with the K&N compared to stock filter, so you need more fuel. With just the slip-on, there isn't that much of a difference in air going in.
 

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Discussion Starter #5
I guess i'm to used to dealing with computer controlled cars that do the adjusting for you. I did think about it though after i did it and taking in that much more air and getting rid of it that much quiker, even if it works fine it would still be wise to be on the safe side and move up a size or two. do you think the needle or the pilot would need altered or just the main jet a size or two?
 

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There are a total of three things that CAN be changed. I don't think you need to worry about the needle or pilot needs to be altered until you do an airbox mod. Your main jet is your MID TO HIGH RPM range. Your needle is your LOW TO MID RPM range and your pilot is your LOW PRM range. Your pipe and K&N will help you best at your MID TO HIGH RPM range, though you will see some improvement in the MID area. As a rule of thumb, it's safer to be richer than leaner, so yes, I would jump the main up to at least the 152.5, but no larger than the 155. But again, that's me personally. I now have 5 UniVents in my airbox and have a 160 main with the needle adjusted up on notch (clip down one grove) to help me out in the LOW TO MID RPM area. Good luck, and like someone said earlier, check your spark plug to see the burn.
 

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Hey Proxpredator what are uniwents (call me stupid if ya want) and if at all possible what are the for and can you give me a web site with a picture of them.
Thanx, Zack
 

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Hey zach, look in his profile and click on his signature, theres pix of his airbox mods in there. As for the univents, they are little round filters. when you drill little holes in the airbox, you just snap in the filters.
 

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I have the W/B pipe and I used to have the k&n drop-in filter until I elimianted the airbox. I ran a 155 jet and it worked perfectly. Just a suggestion.
 

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Discussion Starter #10
thanks for all the input guys. I can usually handle these tasks, however I didn't wanna go through process of elimination. that uses up too much precious time. thanks alot guys
 

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I run the WB and KN. I checked my plug and it seems a little lighter than I hoped. I'm in a bind as I'm racing tomorrow. Does anyone have an exact change they know worked for them running this setup? I'm at about 1400 elevation. I was thinking going with at 152 where it was slightly lighter than I wanted to be, but I'm more concerned with the needle needing changed. Any help will be greatly appreciated. I won't have much time to play with it so exacts would be great.
 

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If you have the K&N drop in element for the stock air box, then you can run a 155 and it should be just fine. That's what I had, and I didn't have to move the clip on the needle. Good luck!
 

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i ran my predator on the dyno w/b slip on and a k/n drop in filter and it made 47.44 hp replaced the k/n with the stock filter and achieved 47.88,so i jetted up from stock 150 to a 155 and the k/n made more power achieved 48.74,and 48.22 stock air filter,so the 150 jetting is to lean with k/n and w/b slip on ,
 

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my dealer said same as too many toys said pred is jetted for sea leavel and at higher altitudes you dont have to rejet with wb slip on or k and n cause of alt change it is a little rich on these mods just make it better
 

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ProX, thanks alot for your info on jetting. It helped me get my bike dialed in very well. Works great now. I was lost on how to dial it in, but it runs AWESOME now. Thanks again.
 
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