Need some HELP.....
After riding for about an hour the engine start to stall, miss fires and cuts off running on dry land. Try to crank and you just get backfires etc. until you wait 40 minutes and it will crank right up and run for 40 to 50 minutes and do the same thing. The engine is not hot, the fan is working but may not be running at time of stall in cool weather. No Error codes show. The Polaris dealer said that most likely their computer will not show any error codes? (Input on this please)
I have removed all battery connections + & -, cleaned, greased and reattached.
Was going to start the fuel thing, and was told the fuel pump & filter is in the tank?,
so.....Also the Service Manual would be nice if still available.
Any Next Step Suggestions?
Thanks

 

This is a shot in the dark but I had a friend who had a motorcycle with a similar problem. It turned out to be the fuel tank vent was clogged. So as fuel was pumped out the tank was put under a vaccum, eventually the pump couldn't supply enough fuel.After sitting the vacuum would leak and equalize and it would run fine for awhile. A extremely lean mixture will cause backfires/stalling ect. I'm not sure how our tank vents are set up though so I'm not sure how likely it is on our machines. An easy test is when it does it loosen the fuel cap and listen closely for hissing, remove the cap then try to start it.

 

next time it does it and it shuts off, turn the key on and listen for the fuel pump to prime. if no sound and when you try later to start it listen again for the pump to prime and if it does then my guess the fuel pump is going bad. a few had issues w/ them. just an idear.

 

I had heard of this problem. People that are riding when this happens always take the gas cap off the each time to check the fuel level, thinking the fuel gauge was wrong. I even did it myself. It did not help the starting back up.
Thanks for the input.

 

This fuel pump thing will be on the list to check next time. So you are thinking the pump just stops running. If I hear the noise then it is working? Is the valve on the fuel rail of any use in troubleshooting? Or am I totally wrong about the rail & valve?

 

[img]i/expressions/face-icon-small-happy.gif[/img] Just for grins and giggles are you ridin' in alot of water? Check coil pack leads and silicone at coil pack! Replace Champion plugs (if so equipped) with Ngk BKR6E plugs, Champions good for lawnmowers only! also as previously stated check for kinks in vent under pod, keep air filter and sensor at back of air box clean. If memory serves me right your 800 doesnt have the Ducati coil pack like the early 700's had! They SUCK! Replaced several of those. Hope this helps!

 

My 05 800 is doing the exact same thing. I took it to the dealer and they couldn't find anything wrong with it. After reading some similar forum posts on this site that indicated that the fuel pumps are prone to failing on the EFI Sportsmans, I threw in my fuel pressure guage and went for a ride. After about an hour, it failed (exactly as the first posts described), so I checked the fuel pressure and it read 0 psi. After waiting for about 20 mintues or so, the fuel pressure returned to the normal 39 psi and she fired right up and ran great. Some of the other posts on here suggested an aftermarket fuel pump that could be purchased at the local Napa for a fraction of Polaris's outragous price, so I guess I'll get one and try it.

 

it does sound like the pump is breaking down but of course check what old polaris tech suggest. here is a post that might help ya.fuel pump

 

Great info. THANKS Everyone!
I have the NGK plugs to change out.
Looks like I need to do the fuel pump troubleshooot thing next or may just do the parts change out thing.
Waiting to see how Junior 88 replacment fuel pump works out.

 

I just replaced the fuel pump yesterday and everything seems to be working fine, so far. I checked the fuel pressure and its right at 40PSI (the manual spec's 39±3 PSI, so its right in the range). I can sort of see why Polaris doesn't sell the pump as an idividual unit because it is part of an assembly that drops in the tank that includes the float, sending unit, fuel filter, etc. and it requires just a hint of mechanical aptitude to change pumps. But I mean just a hint- it is very simple to replace- it's literally a couple wire ties, a new chuck of 5/16" ID fuel line about 2 inches long, 2 new hose clamps, and reconnecting 2 wires. I also replaced the inline fuel pump that mounts to the frame right behind the radiator. (I found a filter at NAPA that is pretty close to the Polaris one- this was a decision based purely on geographics as I live 2 hours from my nearest Polaris dealer here in No Idaho and the NAPA store is about 5 mintues from my house)

I have only ridden my wheeler about 2 miles with the new fuel pump so I don't know for sure that it solved my problems, but this week I am going on a couple hundred mile trek through the Idaho woods on vacation, so I will report back next week with a little more long term report!