My son is 9yrs old but big for his age (about 4'9", 105pds). I want to modify his 05 KX 65 to fit him better. We race harescrambles more than moto, so I really would like to increase low and mid power, if that's possible on that little engine. I also would like some info on tips to set up this bike for a "bigger kid" like my son. He's pretty cramped. Is there any way to raise the bars on this bike? Is a big bore kit the answer for the engine..and if so, any suggestions? He rode a RM 85 a few days ago, and now I'm having to fight off his desires for a bigger bike! I want him to stay on a 65 a little longer being that he's only 9. Any suggestions and recommendations are appreciated.