How do you know oil pump is working on my Yamaha blaster?

I'm not for sure about the year yours is but the 2004-2007 models have a sensor that will not let motor start if it's not working also red light on dash will be light. That's the first thing that we get rid of when building racing quad. Mix it your self and you know it's correct. A block off kit is around $30.00. Good investment....