my 2003 honda rancher 350 es stops shifting when i get to high rpms are going fast so i have to stop and turn off my honda and turn it back on and put it back in nutural why does it do this

 

Check the regulator isn't putting too many volts into the battery, by connecting a voltmeter across the battery and checking voltage as revs increase. You should see 13v to 14.5v. Over 15v and it is overcharging, which causes problems with the electronics of the ECU.