time between top ends

i'm not really sure how long it should be, no one's is the same. but i average a lot more than 14 in a month and i have yet to do one on my bike. also, is 15-20 hours what the manual says? cause mine says every 7.5 hrs and at that rate i would never get to ride. my friend on a yz125 waited a long time to do his and he had very low compression and the bike would cut off occaisionally. don't wait that long, when he took it apart it was nasty looking.

Hi Bulldog,
It seems I am replying a lot. My son's KX 80 went over a year of very regular riding before a top end. And even then the compression was not low. I just wanted to clean the power valve. For a top end job you will need a piston,rings,gaskets,radiator fluid, and a manual. The power valve has to go back together a certain way. The manual will show you how exactly. Total job I think is about 90.00 dollars or so.
One thing that will get a top end quicker than anything is a dirty air filter. Keep your filter clean at all times and you should be able to go for a good while between top ends. I have 3 filters for my sons bike and 3 for mine. I ride a KTM 200 mx/c.

Gary

"Sounds like most of the big 4 are evenly matched... he rides his XR wide open most of the time but thats because of the lack of power. He is going to want to be able to trail ride and do some singletrack again.

Are the RM and KX lacking power or speed on the top end? I would imagine if they are strong low and mid then he can always grab another gear."

They are all 80's or 85's and that is true. Like I said before the CR and YZ likes to be ridden on the upper ranges of the RPM range. The KX and RM have good top end speed also but with the addition of the power valve the two models have good low end power too. I think by having good low end power it really helps coming off of a turn and get good speed quickly to make the jump right out of the turn. And the RM and KX low end power really helps on the trails. From what I have read the YZ and CR caters to the more advanced rider that can twist the throttle more and quicker. As for top end speed I would say that all of the bikes are close. But as we both know on most tracks and especially trails top speed is not that much of a concern. Unless maybe your Ricky Carmical or James "Bubba" Stewart. With those two names mentioned they rode KX's all the way through their ameture years.
In my opinion the average rider will find it easier to ride a KX or RM. KX is my first choice. BTW. We have had really good service with my sons KX80.

Good luck,
Gary
:cool: :cool: