I have a 04 sp600 running like crap it wont idle and i ride hi anywhere under 4000rpm it misses and back fires some times and today I noticed the hose from the valve cover to the air box is shooting some white oil in my air box is there a vent blocked or something any suggestions or help THANKS.

 

What color is the oil on your engine dipstick? Is it whiteish and frothy too? If so, you some how got water in there or have some kind of head gasket leak (or water pump).

Did you flip the ATV upside down recently? How does the airfilter look? The sparkplugs fouled?

 

my engine oil is like new and i did not flip it the filter is fine just where the whose comes in the air box is leaking oil in the box.

 

It could be posible that the transfer passage that lets the oil drain back into the crankcase is plugged or blocked.

 

I have a 2002 sportsman 550 HO. It has been dumping oil in thair box for about 5 months. Been in the shop 4.99 months! We have done everyhting. Check valve relplaced. Slump pump replaceed! Polaris Customer service useless!! Mine is coming in at the left hose, as you are standing behind the bike. It is significant after only 25 miles. The fill tube in the bottom of the airbox is full, plus about 2 oz. It is so frustrating, so if you have any ideas I am all ears
Thanks
BillM