I have a 2001 Polaris Sportman 400 and i will be driving it and it just loses power then the power comes back and it just keeps doing this Have any ideas why? i have changed the fuel filter, air filter, sparkplug, breather filter.

 

might be a lose wire on the circuit board under the head light

 

2001 shouldnt have a circuit board. they did away with those around 1998. when you say loose power do me mean electrical or the motor bogs then comes back? if electrical you could have something tripping a circuit breaker or a wire shorted to frame.

if motor related check the spark plug wire/boot. does it do it in neutral? if not then check your clutches/belt. could be hanging up causing the motor to loose power

 

Fuel pump???

 

Did you change fuel, Maybe you have some water in there?