I have a Savage 21 and im having problems with the motor. When i first start it up it will run good but than after maybe 5 minutes if that the motor will start to steam and than the motor will begin to lose power. If you give it full throttle the motor wants to die out but it wont and than sometimes it will take off or it will just sit there and try to move until i let go of the gas. but it will eventually die out after about a minute of this happening. Anyone have any ideas of what this might be. Please let me know. Thanks in advance!