[airew]

I have a 2010 Sportsman 550 XP that this winter started giving me problems starting when the engine is cold. It seems that the only way to get it running it to give it about 3/4 throttle. Sometimes it will backfire when I'm trying to get it started. After it starts, it will run rough and not idle for about 30 seconds to a minute until it warms up a bit. It seems the warmer it is outside the easier it is to start. It is acting like the computer is not adjusting the fuel air mixture (like applying a choke on a carb). I have tried disconnecting the battery for about 5 minutes to see if that would reset the computer but that didn't work. Note, after it is warmed up it runs like a champ. No problems at all. It is just having issues cold starting. Any help would be great. Otherwise my searches have mostly turned up empty.

Thanks

 

[ChickenHawk]

Spark plug and throttle cable adjustment are the first 2 things that come to mind.

 

[airew]

I have been seeing a lot of posts about the cable. Mostly from people that are having issues with their quads running rough or going into limp mode. But, I will check that. And a spark plug is something easy and probably needs a change too. Thanks

 

[ChickenHawk]

I have the same machine. I don't let my 550 idle for more than a few minutes or the plug will foul. Also, if I just put around with low rpms for a while, the plug will foul and it will be hard to start.

 

[faawrenchbndr]

I have the same machine. I don't let my 550 idle for more than a few minutes or the plug will foul. Also, if I just put around with low rpms for a while, the plug will foul and it will be hard to start.

Mine does not do that,.....I will generally let it idle for at lest five to ten minutes before riding. Never had an issue. Mine also starts within about a second.

 

[airew]

Put in a nice new NGK and made sure the air filter is clean. Still having the starting issue.

 

[1escape1]

Did any of you ever clean your throttle body? I took mine out last week with 2k miles. It was nasty!
Also cleaned the Maf- temp sensor

 

[airew]

I haven't cleaned out my TB. How did you get to it?

 

[faawrenchbndr]

Did any of you ever clean your throttle body? I took mine out last week with 2k miles. It was nasty!
Also cleaned the Maf- temp sensor

What air filter are you using?

 

[bobx2]

You say it runs great once warmed, but does it feel down on power compared to before this issue started? (I know, it's a 550, so it always feels down on power lol ) I'm asking because my 850 had those same symptoms when the timing was off and down on power when riding in high. Didn't notice it so much in low, but that is all about gearing. If all the easy, obvious fixes don't work for you, get the timing checked.

 

[kodiakjohn]

I have had the same problem with 2005 Scrambler 500 and 2011 850 XP, both times it was the intake valves had tighten up. I would suggest you check your intake valves. Hope this helps.

 

[airew]

In case anyone was interested it found out that it was the valves that needed adjusting. I tried a new plug, cleaned the air filter and Polaris re-flashed the ECU. After that it still wouldn't start normally, so we checked the valves and they were way out of whack. I got the quad back today from the dealer and I'm happy to say that it's running like a champ again.

 

[airew]

KodiakJohn, it looks like you hit the nail right on the head.

 

[Treacherous]

In case anyone was interested it found out that it was the valves that needed adjusting. I tried a new plug, cleaned the air filter and Polaris re-flashed the ECU. After that it still wouldn't start normally, so we checked the valves and they were way out of whack. I got the quad back today from the dealer and I'm happy to say that it's running like a champ again.

Out of curiosity what is the build date of your 550?

 

[airew]

In case anyone was interested it found out that it was the valves that needed adjusting. I tried a new plug, cleaned the air filter and Polaris re-flashed the ECU. After that it still wouldn't start normally, so we checked the valves and they were way out of whack. I got the quad back today from the dealer and I'm happy to say that it's running like a champ again.

Out of curiosity what is the build date of your 550?

11-05-09 is on the VIN sticker, I assume that is the build date.

 

[vankemp]

I'm having the same exact issue as the original post here. Mine started last year around this time(September) I took it to the dealer over winter of this year. They had it for about 2 months before they adjusted valves. I picked it up mid mid May this year and it was once again perfect... until this past weekend. I have put less than 300 miles since adjustment and it is doing it again! I'm wondering if its time to go back to a Yamaha!

 

[Treacherous]

I'm having the same exact issue as the original post here. Mine started last year around this time(September) I took it to the dealer over winter of this year. They had it for about 2 months before they adjusted valves. I picked it up mid mid May this year and it was once again perfect... until this past weekend. I have put less than 300 miles since adjustment and it is doing it again! I'm wondering if its time to go back to a Yamaha!

Do you have an '09-'10 550 as well?

 

[airew]

I'm having the same exact issue as the original post here. Mine started last year around this time(September) I took it to the dealer over winter of this year. They had it for about 2 months before they adjusted valves. I picked it up mid mid May this year and it was once again perfect... until this past weekend. I have put less than 300 miles since adjustment and it is doing it again! I'm wondering if its time to go back to a Yamaha!

My valves would continue to get out of adjustment after a 100 miles or so. I ended up taking it back to the dealer 3 times total. The third time they finally figured out that I needed major engine work. Search the forums for my other post for more information. There are some posts there that explain it really well. But basically in 09 and early 2010 there were some made with bad heads that were allowing the valves to get out of whack. I ended up saying good bye to mine and bought a Can Am Outlander Max 1000 XT. I miss my Sportsman. I wish I could have waited a little longer and got the Sportsman 1000 Touring XP. Oh well.

 

[TXRonnie]

Another one bites the dust. The 550 valve problem just keeps getting bigger and bigger with 09 and early build 10's. I bet there is still more out there we have not heard of.

Ronnie

 

[vankemp]

I'm having the same exact issue as the original post here. Mine started last year around this time(September) I took it to the dealer over winter of this year. They had it for about 2 months before they adjusted valves. I picked it up mid mid May this year and it was once again perfect... until this past weekend. I have put less than 300 miles since adjustment and it is doing it again! I'm wondering if its time to go back to a Yamaha!

My valves would continue to get out of adjustment after a 100 miles or so. I ended up taking it back to the dealer 3 times total. The third time they finally figured out that I needed major engine work. Search the forums for my other post for more information. There are some posts there that explain it really well. But basically in 09 and early 2010 there were some made with bad heads that were allowing the valves to get out of whack. I ended up saying good bye to mine and bought a Can Am Outlander Max 1000 XT. I miss my Sportsman. I wish I could have waited a little longer and got the Sportsman 1000 Touring XP. Oh well.

So... If I become the next "victim" as implied, what is this extensive engine work going to cost me in the end? I just bought another Polaris unit. I wish I had known the shelf life is only 2 years or less!!! This really angers me, as this is my wives unit and has not been abused in any way. I had a yamaha grizzly before I bought my other new Polaris this spring, and it had triple the miles on it, and has never had ANYTHING wrong with it.