I adjusted the throttle cable so there was just 1/8 free play before the rpm's would pick up but I'm still getting some backfires. Any other ideas or should I just let the dealer sort it out. He is quite a trip from here.
Thanks Dave

 

I'm not sure what to tell ya Dave, If it was mine I'd take it back to the dealer and tell them to fix it , but I'm only 20 miles from my dealer! If they can't figure it out tell them to give you a new one! lol Could it be that the timing is'nt set right?
Mine has not backfired even once! I don't think it's the gas quality (octane).
IMO have the dealer MAKE IT RIGHT.[img]i/expressions/face-icon-small-mad.gif[/img]
You paid good hard earned money for that bike and part of that money is for the service you should get! Polaris should fix it!
Some of these set up guys probably have their own little shortcuts and an I know how to better, attitude and may have done it their way instead of by the book!
I would be mad as Hel-

 

Sorry dave I went off on a little tangent like that but I hate to see someone pay for a new bike and have problems like that! I know It's probably not the set up guys fault but something was put together wrong somewhere!
Take care
rancher.

 

if this is for the new 09' xp then take it back the dealer as they wont cover warranty if they you are working on it. might be they have to remapp the comupter or something?? let us know.

 

Good luck Grizzly600. I would like to know what your issue is so that I can look out for it when my machine arrives.

IronBear.

 

Mine also backfires occasionally,would be interested in the fix my dealer is 100 miles away.

 

Mine used to backfire too. I had the dealer come here and pick it up, they said they adjusted the throttle cable, then they brought it back. It has backfired about two, maybe three times since then, little ones. I run either 91 or 93 octane in mine, and only 87 octane int the 700. Now mine has about 20 hours and roughly 160 miles on it.

 

Hi opie 1 har,
I've run mine on 91 octane from the get go. I adjusted the throttle cable as per HIGHOCTANES post but in a ten mile ride the other day it backfired twice. I may just have to take the Ferry down and run it out to the dealer and have them do my tire change over also. My mudlites arrived!!! It is a bit annoying that it's backfiring. The first time it scared the crap out of my since I was out hunting and it sounded like a shot going off behind me[img]i/expressions/face-icon-small-smile.gif[/img] thought I missed seeing a nice buck.

 

Id take it in,it sounds like it is a fueling or spark table issue. There is a lean backfire and a rich backfire,generally a backfire when you let out is a rich backfire caused by the cylinder loading up with fuel. But it could be a lean backfire caused by the ECM pulling too much fuel with rapid reduction of throttle Could be as simple as a TPS adjustment,small vacuum leak or the baro/temp sensor ect.. Is it not throwing any codes? Long story short,if you aren't pretty good with EFI and /or have the right tools your best bet it take it in. Could be numerous things.
Mine backfired once the other day for the first time,it was the coldest day I have ridden,also i have 93 in it, I previously had 89. So far I have decided to go back to 89,throttle response was crisper and power felt better.
It happened when I quickly released and reapplied the throttle. It didn't stumble or anything,just a pop. This leads me to believe the ECM was a little behind in making fueling and/or timing calculations. An improperly adjusted TPS can cause this as the computer isn't getting the correct throttle position information. Wide variations in temp can make this pronounced IMO because even though EFI adjusts for temps if the ECM is getting bad throttle position data then everything else it thrown off. You might ride that machine in warmer eather and not have a noticable problem.
For the heck of it pull your plugs and look at them. I've heard of some problems with the XPs caused by numerous people starting them at the dealers to hear them then shutting them down without warm up. That loads the cylinder up with fuel without the plug getting hot enough to clean itself leading to a partially fouled plug. Good to look at the plugs from time to time. Down and dirty plug reading instructions...if they look white or like new clean it's way too lean,if the have a thick coat of black carbon on the ceramic insulator and electrode it is too rich and possible partially fouled. You make have some black on the strap and the area where they threads protrude into the cylinder,this is normal. They should be light brown or dark tan on the ceramic insualtor around the electorde. Reading plugs like this will give you a general idea of the overall fueling but doesn't really detect transients very well. ie to properly check WOT fueling you have to run at WOT and shut it down while still at WOT.
If you are unsure about the plugs post up some pics for us to look at.
To get at the plugs you need to pull the body plastic that the shift lever goes through. Pull the seat and remove the 10mm bolt at the rear of the panel. Pop the cover off the top of the shifter handle and remove the Torx head screw. Slide the shifter handle up off the shaft. Remove the 3 plastic push pin rivets near the bottom and carefully pull back and down on the panel so its tabs clear adjacent panels. Then just slide it up off the shift lever. The plugs wil be right in front of you and easy to get to.

 

OK my dealer got back to me right away and said that I have to follow the Owners Manual with the process for adjusting the throttle setting. Apparently the gap between the stop and the throttle body is very critical and the gap has to be between .o79 and .110. First you adjust the throttle cable so there is no gap between the stop and the throttle body and then back the cable adjuster off until you get the desired gap. You have to flip the throttle while you are doing it to make sure the gap is there if you drop the throttle off quickly. You can see the contacts open and close as you work the throttle so when you let off the contacts close, so if the cable is set too tight the contact might not make properly and this can cause the backfire situation. I've adjusted mine but I haven't been able to go for a ride yet. I'm just heading off on a hunting trip so I won't ride it until the 6th of Dec. Fingers crossed this is the solution. Now that the important stuff is done it's back to work. With the cable adjusted so you could feel 1/8 play the throttle body was pretty much up against the stop so if you let off quickly and the quad decelerated under engine braking it might not have real good contact.
Take care,
Dave