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Discussion Starter #1
WOw scared the crap out of me I thought somebody real close fired a big gun off by my head.
that is the first back fire I have heard out of this thing 850 xp
anybody else have had a backfire

indy
 

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It backfired? WOW, I would park it where it sits and run away..... and let me know where the that place is. :)

Very common problem for about the first 25 hours or so. Hotter plugs help it but it will go away on its own. No need to worry.
 

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Discussion Starter #3
just joined the forum yesterday
just had a simple ?
I am sure somebody will chime in with a answer
 

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I think I already did. Apparently the smiley face did not convey that I was kidding with you.

They run rich for the first little while and when you let off the throttle it will let a little gas into the cylinder that some times is not ignited. Next revolution of the crank and bang. As the motor gets a bit broken in this will let up. As I mentioned, a hotter plug like the champion #8 or better the NGK Irridium will help out a bit as it more fully burns the fuel it seems, can be of help.

That being said it will go away on its own. Just try to avoid hard on the throttle to none at all and you should be good.

Welcome to the forum, its a great place and you have a great quad. I know cuz I have two.
 

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Mine did the same thing maybe a half dozen times. After my first service no more. I did ask specifically for new plugs. He said the plugs were black.
But ya its normal.

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Yes my scrambler 850 was doing some crazy backfire when not broken in, but now in 4000km it never happened again, only small ones when hitting the rev limiter...
 

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Discussion Starter #8
Thanks all
 

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Once it is properly broken in and the valves properly seated, all will be good.
 

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This confuses me. I never once had my machine backfire.

But it seems like everyone on here uses regular gas in their 850's. Where I have used premium since day 1. Maybe its connected?
 

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I've had backfire issues from the negative battery cable being loose and not providing a good ground for the EFI. Otherwise if its new then i think you got your answer from others ^.
 

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Discussion Starter #12
I only had it do it once in the woods at 510 miles sounded like a gun went off
 

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I run super in mine, back fires once and a while still. did it a lot when it was new. seems to do it after running the same speed for a little while. like half throttle for a minute or two
 

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my 2012 850 backfired a little hear and there when new but didn't last long I have 1600 km now and cant remember the last time it backfired.
 

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This confuses me. I never once had my machine backfire.

But it seems like everyone on here uses regular gas in their 850's. Where I have used premium since day 1. Maybe its connected?
I use premium and my wifes 2013 850xp back fires.. Only has about 15 hours on it though..
Im hoping to break it in right,,, real soon,, haha

Plugs were black and fouled and replaced at first service last week..
 

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Mine backfired well after 25 hours. There is a computer reflash your dealer can do that will eliminate it. If you are under warranty, it's free. I waited too long thinking it would go away when I built up some hours which it didn't so I had to pay. Only $40 so not a big deal. No backfires since.
 

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Just got mine ( the wife's really) back from the dealer and I asked about the backfiring. They said all they could find is fouled plugs so they changed them at my expense. It's a 2 month old machine with 130 miles on it and I have a2 year warranty. I'll be asking them what's up !!


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Tell them to look up the reflash. Should only take a few minutes to do the update and you'll be set!
 

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I'll do that.. Thanks for the great info.


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