hi so i just purchased a 2003 lakota sport for 700 bucks. It needs new rear rims and tires. i Just did a oil change and changed the spark plug oil filter and cleaned out the first air filter. When i drive the thing now when im in like third or fourth gear high it will randomly shoot up in rpms for a second its weird. I dont know whats wrong with it? what else should i change i just got it and this is my first atv any help would be greatly appreciated. I also would like to start modifying it so i will take all input there as well..