Hi I have an 07 sportsman 500 efi and I noticed this weekend that sometimes when I'm giving it full throttle the tach will suddenly start fluctuating alot and then drop down to zero rpms and then the battery light will come on. If I let off the throttle it will go back to the correct rpm(I assume) and battery light turns off. Doesn't seem to have any issues with performance or anything and the battery has never died on me it always starts. But then again I just bought it this year and only have about 5-6 hours of plowing and maybe 20 miles of riding on it so far.
Any ideas what this could be?
Any ideas what this could be?

