ATV Polaris 850 Suddenly Dies

After riding about 20 miles on a hot day my 2011 Polaris XP 850 suddenly died. There were no indications of engine problems and the radiator hadn't overheated. If I waited a few minutes it would start and run normally but it would die again in a few minutes. I installed a new belt, adjusted the TPS and installed a new breather kit because I read about someone with the same issue also had the oil in the air box problem. On the next ride it still had the problem.
Reading the forums I found another person with the same problem corrected it by replacing the fuel pump. They thought that on a hot day the fuel would warm up and the old, worn out fuel pump would overheat and cause a possible vapor lock condition. I got a new replacement fuel pump assembly ($185) and on the next 40 mile ride the problem appears to be fixed. I made this video because it might help someone else that encounters the same problem.

[@noelrubalcava3794]

Just finished replacing the fuel pump, bike sounds alot better, thank you very much

[@dalechristensen3433]

It's a big job and I hope it solves all your problems.

[@noelrubalcava3794]

Was this the last problem Your 850 had? I Changed the airbox with the new kit and replaced the circuit breaker already

[@dalechristensen3433]

I had a 2 year old battery fail after replacing the fuel pump. I didn't have any problems with my 850 for the past year.

[@noelrubalcava3794]

Have gained 30miles with no problems since the fuel pump replacement, is there any advice you should give after replacing the fuel pump?

[@dalechristensen3433]

I just finished a 40 mile ride and haven't had any problems since I replaced the fuel pump about 400 miles ago. If you have any other problems it most likely won't be caused by a bad fuel pump.

[@stepup2903]

Same problem, I work on a 500 and it starts goes for like 10 min and then bam it dies and also it gets hot very quick, hope a new fuel pump will do it

[@noelrubalcava3794]

Do all 2011 Polaris 850 have this problem? Mine is stalling out just like yours

[@dalechristensen3433]

Only those with a failing fuel pump. I tried several things to correct the problem but the fuel pump replacement was the only thing that worked.

[@noelrubalcava3794]

Dale Christensen the fuel pump sounds different and quad works when I let it cool down

[@dalechristensen3433]

It looks like you've had this problem for a couple months. It costs some money and takes some time to do the work but it's better than needing to be towed when it won't run.

[@noelrubalcava3794]

Fuel filter went bad on my 850, I feel like changing the pump as well to Rather feel safe than sorry, should change the whole assembly like you did?

[@dalechristensen3433]

It takes some time and work to reach the fuel filter so it would be a good time to replace the fuel pump and filter. It costs a lot more for the fuel pump but you won't need to repeat if the old pump is failing.

[@heathhaag1639]

How often do you change fuel filter? I have an 18 850 with 1400 mi

[@mauriciod3865]

Same problem on my side by side, it would stop running, I would take the whole pump assembly out of tank, tap it on a tree and put it back in and it would work. Decided to a new pump and runs great.

[@MegaDennis2008]

i have got a problem with my quad dying i put new gas in it but it still dying I'm guessing its a key problem cuz i lost the original key so now i need the spare key

[@cameronabbott7882]

I had similar stalling issues with my 850. This after the service shop replaced a rogue starter that would engage with no key in the ignition. The Polaris dealer trouble shot the stalling issue with no solution, I happened to noticed one day that the kill switch wiring coupler was loose. I fully engaged it and made sure it was clipped in. I have not had a stalling issue since. I will assume the kill switch was opened for the starter install.The starter was replaced a few weeks beyond the warranty period with no help from Polaris. I was not impressed with my service dealer but the machine has run awesome since. Hope this helps some fellow riders.

[@dalechristensen3433]

Thanks for the good information on the kill switch. It wasn't easy for me to find this solution with research and repairing other possible causes. Your Polaris dealer would have the same difficulty. I posted this video to help with the research. A couple weeks ago I rode almost 200 miles with no problems.

[@JosephBoyd-e5b]

Mine will not stay running after I jump start it, new battery and all some days it'll run good until I shut it off other days it dies right after i take off the battery cables

[@noelrubalcava3794]

My problem is a dirty fuel filter, but do I really need to take the air box to get to the fuel tank?

[@dalechristensen3433]

The bolt holding the upper left side of the fuel tank is almost impossible to remove without taking off the air box. The tank needs to be moved to the right to be able to remove the fuel pump and filter. I decided it would be easier to remove the air box instead of working with limited access and I'm glad I did.

[@noelrubalcava3794]

Dale Christensen how long did it the whole procedure last?

[@dalechristensen3433]

It took about 4 hours to complete. I already had practice removing the plastic but it was the first time removing the air box.

[@noelrubalcava3794]

Dale Christensen Alright, already purchased the fuel filter but the dealership offered to change it, thanks for your cooperation though

[@chrisatkins1943]

Hey man that white weep hole on top of your fuel tank what hose goes on it, I bought a used one and there's nothing on that white fitting

[@dalechristensen3433]

The white fitting, that is not part of the fuel pump, is a vent connection. I have clear plastic vent lines that all seem to terminate in the headlight pod.

[@chrisatkins1943]

@@dalechristensen3433 thanks man

[@grumpyoldman336]

Ive had two of these pieces of garbage over the years.. a 2010 850 that was nothing but problems and then traded that in on a 2012 which spun the timing chain gear on the crank after 2 hours of riding so.. yea I got it fixed and got rid of it and picked up a Rubicon and 10 years later.. not a single issue to report.

[@stevecorbett702]

Thank you!!!!! I was trying to find what was holding the tank in for the last hour.

[@tbysor]

Same thing happened to mine and I had to walk back 18 miles! I suspect a fuel pump defect. Has anyone else had the same experience?

[@dalechristensen3433]

I was lucky to ride with someone who could tow me back out. I found only 2 other messages on forums from people who had the same problem and resolved it with a new fuel pump. I haven't had the problem again.

[@tbysor]

Thanks for your reply. I have owned over 5 Polaris Rangers and ATVs and this one-the newest(bought last Spring) has given me problems-same thing. In the past I have left it for 5 mins. then it started and ran just fine. This time I waited 15 mins. and still wouldn't run. We use them on a large ranch.

[@dalechristensen3433]

There's one indicator to a failing fuel pump. When you first turn the key on it will make a buzzing sound as the fuel pump builds up the fuel pressure. If you don't hear the buzzing sound or it sounds different then the problem might be the pump. My brother's Arctic Cat (non-EFI) had a failing fuel pump and the sound was the only indicator. You might need to release the pressure before turning on the key to hear the sound.

[@tbysor]

Thanks for the indicator. I'll certainly be more careful. Never had such a problem before with Polaris. Makes me skeptical of the new models!

[@acoustic4037]

Same problem with 2015 570, brand new with 24 hours on it (202 miles). One exception- mine was dead never to run again. Tested fuel pressure, had 20 psi. Dis-and Re-assembled (thinking the o-ring was leaking past) and then got 10 psi. Repeated process, and got 46psi but it stalls idling. Waiting on new fuel pump to arrive, for a brand new machine. My first and last Polaris product. People can say what they want about buying American, but I am pretty sure if I had got a Honda, I'd be trouble free, as it should be. And if Polaris is listening, I will tell any and everyone how I feel about this. I also did call the Polaris corporate consumer line to no avail.

[@HoundingNewMexico]

My 850 seems to be bogging out and gets hot I was thinking I used bad gas and started using higher octane but same problem still what do you think could be the issue??

[@dalechristensen3433]

My 850 bogged out and died when the fuel pump was failing. You might consider checking your air filter and spark plugs first. The fuel filter is on the fuel pump assembly and if you want to clean it you should probably just replace the entire assembly. This would rule out any problems with the filter and pump. Also, if there's a leak in your fuel line it would cause the problem you have.

[@HoundingNewMexico]

@@dalechristensen3433 thanks a lot! I will definitely check that! I’ll get back to you once it’s fixed and let you know.

[@SuddenKhancer]

I have this same problem and need some help. I’m getting Getting intake pop and running rough from stop to getting going. Very choppy start to get the rpm’s up to engage the clutch basically. I’ve changed the filter, oil, plugs, and put a quantum fuel pump in today. My fuel pressure is good at 58psi now but still running rough.

[@redsox63]

Believe I’m starting to have the same issue on my 570 sportsman...will run fine for 20-30 mins then all of the sudden it develops a miss and it will stumble and spit and sputter. The next day it will be fine again for the same amount of time. 99% sure it’s losing pressure after warmed up. Got a pump assembly coming tomorrow, will test pressure cold then let it run for a half hour or so then test again to be sure.

[@dalechristensen3433]

It would be nice to know if the new pump solved the problem like it did for me.

[@redsox63]

@@dalechristensen3433 hopefully will find out this weekend!

[@Huntercantell576]

Same thing happend to mine I changed the pump did not change it

[@redsox63]

@@Huntercantell576 mine ended up being broken wires going to the tps sensor. Replaced the pigtail going to that sensor and it fixed it.

[@ogmudder6839]

You won't believe it but the gas in tank is getting hot,heat wrap the tank and exhaust.

[@liquidstatic1617]

Why would you heat wrap the tank and exhaust?

[@puffdaddy1693]

I had same problem on 2015 rzr 900. it is an o-ring on fuel pump that becomes dislodged causing pump to loose nearly all pressure. Walked out of the desert TWICE. first time dealer told me what happened and the replaced o-ring and assured me they have never seen that before an said it should never happen again. few months later happened AGAIN. Polaris customer service are the rudest people I have ever dealt with. They agreed to send me a new pump finally, MUST BUY ENTIRE PUMP ASSY FOR $450 otherwise. I installed new pump and carry the old one as a spare after disassembling old pump and installing two rings. The pump assy can be dismantled and replace pump with $50 pump motor off ebay if pump motor dies.....don't pay the outrageous price from pooplaris. Side note all Polaris machines use pretty much the same pump assy

[@dalechristensen3433]

That's good to know about because I just bought a 2019 RZR 900.

[@bradjohnson8020]

I have a 2015 850 sportsman it has 256 km on it total and being told the motor is gone. Never buying a polaris again!

[@bearbait2221]

If you keep your fuel tank more than half full this will never happen gas cools pump keep this in mind on hotter days

[@dalechristensen3433]

I tried that on a ride before I replaced the pump and it didn't work when climbing up hill. The new pump is still working great.

[@georgedeitrich4647]

That is fine for those that only do a 10 mile ride. But we ride 80 to 100+ miles after leaving camp

[@bearbait2221]

@@georgedeitrich4647 bring extra fuel simple

[@georgedeitrich4647]

For people that ride only 10 or 15 miles from camp they is easy to do. We ALWAYS fill up before leaving camp and ride about 100 miles and more.

[@jesuscano7349]

Hey I think I have same problem

[@jaxrules2892]

My dad had the same problem

[@oldirtyguru7004]

Ok so it is my fuel pump I was confused why it would start sometime and others it would just crank

[@oldirtyguru7004]

Also my clutch is bad so at this point I might just rebuild the whole thing so I don't have anymore problems things only got 71 hrs on here pretty much brand new

[@dalechristensen3433]

The posts I read said they thought that the pump was over heating or foaming the fuel. If you wait 15 minutes and it starts okay, it might be the fuel pump.

[@oldirtyguru7004]

@@dalechristensen3433 idk I let it sit over night it turns but never starts it'll some what run if I keep the starting motor engaged otherwise it doesn't run at all

[@dalechristensen3433]

@@oldirtyguru7004 It doesn't sound like an ignition problem. My 850 did the same thing when the fuel pump went bad. It could be the fuel filter and that's located at the bottom of the pump.

[@oldirtyguru7004]

@@dalechristensen3433 thanks I'll keep that in mind when I take mine apart

[@kayzee2775]

This happened to me just few minutes ago and it's not even my fucking ride now I gotta pay for it ...my buddy was driving like a dumbass I don't know what exactly happened yet but I gotta figure it out tomorrow

[@kayzee2775]

And thanks for the video

[@russellabernathy3241]

Get a Yamaha I was the largest Polaris dealer in the USA they suck pure junk

[@danielalvarez3248]

R.i.p clutch animal 🐴😂