Hello! I am new to the board and owning a polaris sportsman.

I bought a used 2004 700 EFI with 76 Hours.
First time out - Ran Great
Second time - ran good for awhile, then started missing. I turned it off and back on and never had the issue again.
Third time - Ran great
Fourth time - ran great in morning, parked and went hunting. Came back 5 hours later and started up fine but would not run.
It will now start, but sputter, miss , back fire and stall. Checked the spark plugs and they were soaked, even outside the plug. They were champions so i replaced with factor NGK. This did not resolve the problem so i had to push back on to the trailer.... bad day!

Today i siphoned all the gas out, added seafoam and fresh gas. Still the same problem. If i press the throttle real fast, i can get it to slow build RPMs but it will eventually stall.

Your help would be greatly appreciated. My gut is that it is electrical... coil?

Justin Taylor

 

Welcome! What usually happens when they spit back and sputter and at times die out is a short in either the T-bap harness or connector or the Tps harness. The wiring is way too thin to take the constant vibration and can have bare spots or wiring can break internally. Look at the "sticky" above this section on the efi wiring problems on the 700 and 800. Plus can be shorts in the crank sensor harness where it might rub against the starter. You can look at the harness wiring and check for any obvious bare wires shorting to metal and if any individual wire might have a "soft" feel to it indicating internal breakage. OPT

 

There plastic around the wire is rubbed up near the frame and back by the plug. It does not appear that any wires are broke though.

I have attached pictures as well as a video of what happens when i try to start it.

https://docs.google.com/open?id=0B6z...WtValNqR1VhbEE
https://docs.google.com/open?id=0B6z...VA2YmIyWHpoQlk

Video of issue
https://docs.google.com/open?id=0B6z...1FxUDFfazN5aU0

 

This looks like your problem,especially the wire that looked deformed not just the bare wire. All it takes is for a wire to ground out,wire not full in the connector itself or one that is melted from with in to run good one minute,popping back the next.. You can always splice into the bad wires, using heat shrink connectors and see how it runs. If you buy the kits (Polaris,which I wouldn't recommend and the heavier duty aftermarket kits, have the connector and about 6-8 inches of wires. OPT

 

Tonight I started pulling all apart in preparation for my new harness that is on the way. I decided I should go ahead a clean the fuel tank better. I got a nice surprise when I pulled the fuel pump. In between the outlet and the pump is a regulator. Connecting the regulator are fuel lines. Both are black lines and when i touched the bottom one, it turned into goooo...It is like black play doe!! I looked in the fuel tank and i can see pieces. I also noticed there is no flat sock like i have seen in other pictures.. There was just a piece of white plastic laying in the bottom. Shouldn't these lines be clear?

 

Sounds like a good old ethanol problem also. You might try replacing the lines and fishing the filter sock from the tank bottom. If the fuel pump needs replacement, Airtex pumps is what most of the members used. You can search up fuel pump problems and think they show the Airtex number they used. Think this is close. OR this one.http://www.autozone.com/autozone/parts/Airtex-Master-Fuel-Pump/_/N-8vcz2?itemIdentifier=21929&_requestid=707702 OPT

 

this sounds like the problem i'm having with my 500 polaris

 

"If" its an efi atv and has intermittent problems, runs good,then spits,sputters,etc, then could be a t bap or tps sensor harness problem. Or fuel pump problems if it dies on you or won't crank. A lot more can happen on these machines than carb atvs. Look at the "sticky" post above this section on efi wiring problems. This affects all the efi machines from the 500,700,800,etc. OPT