Look at the easy stuff first. If you ATV is charging , it might just be time for a battery. For what they cost I,m glad if one last 3 seasons.

What year is your ATV? When I bought my ATV it had a dead battery,but being lazy I road it for a month by just pull starting it before getting a new battery, but the ATV still behave normal in every way with a dead battery in it.

 

its an 03 trailboss 330, and i have noticed that when the battery is weak it doesnt run well at all and sometimes wont even start with pull rope. after i charge battery it runs like a champ again til the battery get down again. im gonna check the voltage tonight and pray its just the battery ($27.00)

 

A 03 may use a ECM ,those ATVs do not run right without a heathy battery I think.

 

I could be mistaken, but I do not think they were using Ecm's in 03. My manual covers up to 03 and makes no mention of an ecm. I have searched the text as well as looked at all the schematics. I could easily be mistaken, TLC knows Polaris much better than I do, but I don't think it is going to have one.

I was assuming something was wrong with the charging system because he could charge it up and it would work fine for a while, then slowly go down as it was used. If it was a bad battery, I do not think it would take a charge enough to be able to start and run for an hour.

These are the exact same symptoms mine had when my stator was bad. When you get home, look in front of the radiator. There will be a small black box with several wires going to it. Unplug the yellow and the yellow/red wire. Connect a digital ohm meter to the wires than run back towards the engine. It should show a resistance of .013 ohms. If it shows as an open circuit (the needle does not move), your stator or the wires going to your stator are bad.