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Discussion Starter #1
First I put theie polaris muffler on and my bike ran great. Then I went with the K&N air filter. I followed the directions to the T. Started up my bike and started to smoke out the muffler. I thought oh, time to re-jet. Take my bike to get re-jetted at dealership. They said all they needed to do was put a 150 main jet and that was it. Brought bike home and started it up and still smokes. Called dealership and they said oh that's normal, it's burning more gas, that's why. I put stock filter back in and the smoke disappeared. What is going on? should I forget the K&n filter or what.
 

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That's very odd.. BTW, the stock carb jet IS a 150, so the dealer was giving you a line of bull, unless it was rejetted prior to you getting it. And since you're in Missouri, I don't see why they would have rejetted it before selling it to you.

What color is the smoke? Mine was smoking pretty bad when I had my DynoJet kit in it because it was running way rich. My friend said he thought it was a diesel. :)

Rob
 

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Your K&N may have too much oil on it restricting airflow, clean it and very lightly oil it, try again.
 

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I noticed mine was smoking a bit too. It's really noticeable after I turn the quad off cuz smoke comes slowly out the ass end. Hmm.... maybe its the av gas im runnin'
 

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Discussion Starter #6
My bad, I meant he put a 155 jet in it. sorry. Just got it back and he ended up putting a 152.5 main jet. It seemed to do the trick. I was a little worried for a while.
 

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Im running av gas with a 167.5 main and a 50 pilot. hmm It seems that my quad was running great until I changed it to the 167.5. However my quad was running the best with the 167.5 but it smokes a little. The smoke is a white color and it only does it when I first start it(till it warms up) then when I turn it off. I also noticed that when I put my finger in the exhaust tip, the residue was sort of wet or moist even though i hadnt ridden the quad since last week. does anyone have any thoughts on this? I know its not the av gas cuz I mix it the same way everytime and it runs excellent up to the point when I changed the main jet to the 167.5 from the 157.5. Thanks.
 

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Sounds like it's running rich. Try going back to the old jet and see what happens.

EVERY time I've made a jetting change to my Predator, I've ended up putting it back to stock, because it always ran better before I messed with it.

I'm tempted to try that Air Force kit, but since the DynoJet kit did nothing for me, I wonder if it'd just be a waste of $100.

Rob
 

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I'ver heard the Air Force Kit is 10 times better than the Dyno Jet. Nobody seemed to like the Dyno Jet and everybody seems to like the AF Kit. I am gonna try it.
 

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AV gas is 100 octane, designed for piston powered aircraft. The blend helps planes to operate at high altitudes. Its not designed for ATV use.
 

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I was told by my dealer to only burn 87 octane gas in my atv
 

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You have to be careful with high octane fuel (above 104) cause you can burn the valves or put a hole in the piston (if they are stock). Also not sure if using 87 octane is good for the Pred. because the combression is 11:1 and requires a higher octain.
 

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(sigh) Ill say it one more time and leave it at that. "AVGAS is for Piston powered aircraft." It is not designed to go in your mommies firebird or your quad. (Mickey Dunlop at FST will tell you the samething.)

The stock piston compression of the predator is 10.8.1
 

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I don't remember mentioning AVGAS in my post. 11:1 or 10.8:1 lets not split hairs. It's not considered VERY HIGH compression but is still high compression. I wouldn't run 87 octane in an engine with 10.8:1 compression. Super at the pump would get it. I used to run a 1/4 car and couldn't run it on pump gas. I would mix AVGAS (it came as 116 octane) with pump gas cause it was way less expensive than buying 110 octane that was $3.45 a gallon back in 1984 in
New York. I only caution people thinking of running high octane (above 104)in engines with stock components because you will burn the the valves!!!
 

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Hmm the only reason Im runnin' av gas is cuz its about 50 cents cheaper than premium where I live!! I've run about 40 gallons of av gas through my quad now and no problems. I think jeremy is right about it smoking till it warms up cuz it stops after a bit.
 

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you guys bicker like old women! ha ha ha ha ha
just drive it like you stole it, and have fun!!!! thats what they are for right?ha ha ha ha ha ha
 

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All I run is avgas as well.Avgas is designed for high compression engines like aircraft.Believe me, I work on aircraft and if you are running anything less than 92 octane you are not going to get the best performance from your machine.On that note racing fuel is over 100 octane rating.
 
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