My 2005 500 HO sportsman seems to push out blue smoke from the exhaust and then it seems to stop. Next thing you know its smokeing blue smoke again, Mostly under a load like climbing a hill. Then it clears up. Engine starts good and idles good. Seems to have good power. If you did not see the blue smoke or smell the oil burning you would not know anything was going on. Engine oil is not overfillled. I changed the oil and used 0-40 synthetic polaris oil. Anyone have any ideas. I bought the four wheeler used with only 580 miles on it a couple of weeks ago.

 

is your bike using oil? could be valve seal issue, maybe a damaged oil ring. any oil in the air box? make sure crank vent isnt blocked.

 

When I purchased it there was some engine oil sitting in the air box and it does use oil.

 

HI There. I'll bet the people you bought it from new it was burning oil ****es me off when people do that. I've been burned before too. Ken Kinsey Atlanta Mich.

 

ITs possible that its just blowing carbon and crap thats been building up in the carb cylinder and exaust sea foam will do that to a motor if you add enough or put it into the carb. the machine doesn't have that many miles so mabe its just had some gunk buildup. Prolly not though. What I would fear the most is the prevous owner just used any oil they had when and if they ever changed it. I have little experiance with the 500 motor but they say that if you don't run a good 0-40 or 2-50 oil it will hurt them. But hey it runs good just keep her topped off and maby change the plug a little sooner and it will be fine.

 

I also have a 04.5 and it was doing the samething ran good started good ran like a new one but would smoke on and off i thought it would be the valves seals it was not the oil ring on the piston was wore slap out had to bore and install new piston and rings runs just like it did but no smoke the commpression rings where wore but could have been used but i went on and did it right while the engine was a part

 

In My 05 service Manual it says.
Excessive Smoke and Carbon Buildup
1: Excessive Piston-to-Cylinder clearance. I do`nt see this should be the issue as it does`nt have that many miles on it.
2: Wet Sumping . This is a good possibility.You might want check and make sure the oil pump is working correctly to scavange the oil back out of the crankcase.
3: Worn Piston or Cylinder. A compression or leak down test would determine if this is a factor.Do a compression test then put about a 1/2 dozen squirts of oil into the cylinder{s} and do the compression test again.If the compression increases 20% or more then it would be the rings/Piston.
4: Worn Valve Guides or Seals.Again I do`nt think it has enough miles on it for this to be an issue.
5: Restricted Air breather. I would suspect this above everything else.Be sure the crankcase vent is open and not kinked or plugged in any way.
6: Air Filter Dirty or Contaminated. Another possible cause as a dirty air filter can cause a vacuum in the intake side and cause oil to be sucked up past the rings.Make sure the Air filter is clean.
7: Having a Service Manual is a very nice thing.LOL

 

water in the engine at one point would do it, as well as using the non synthic oil would make it wear faster.