Newbie to Polaris with ??'s

[TxFire]

Howdy all. I recently purchased a 05 Sportsman 500 with 60 something hours on it. Seems to run good and I have had a couple small issues...one being no power when it gets wet and often dies in deep water....which really dirves me nuts. I searched and found a few topics here of things to check on, so that helps.

Right now, it's at around 125 hours and the tool symbol is flashing and I need to service it anyways. Can anyone give me recommendations to the proper/better/best oil and air filters to use? And also, what type/brand of oil is best for it??

Right now it has a K&N filter on it and when I took it off earlier to look at it, it has a gas taint to it and the unit actually has backfired a couple times before, after hitting water and it dies....and I have changed the spark plug also.

One more thing....in the bottom of the air box, where the drain is, there was some reddish looking fluid in the drain port, almost looked/smelled like hydraulic fluid...would anyone have an idea to that??

I appreciate anything anyone wants to throw out there!! And I'll try my damnd'est not to act like a newbie!! I'm an administrator of another forum...so I know how it is!!

Thanks all.....I appreciate it!