i have problems with 2005 polaris 800 sportsman it will start when jumped with charger but will die as soon as the charger is disconnected. Check engine light is on and don't have a tester to read codes. I also just replaced the battery with a new one. There also seems to be air pressure blowing into the air filter chamber it doesn't contain any oil just some air. Just curious if it may be blow by. Any ideas will be greatly appreciated

 

Welcome to the forum! Turn the ignition key from off position to on position(not start) 3 times quickly stopping on the 3rd time. Any codes stored in the ecu should be be displayed. Crankcase pressure does vent into the air box from the hose going to the valve cover. Plus not unusual to have a brand new battery that could be bad,plus make sure the battery connection are tight! Could be as simple as that or a loose frame ground wire. Hopefully this can give you something to start with. OPT