KX85 rebuild tips

Hey guys,


I have a YZ250 and my little brother has a 07 KX85. I know about rebuilds on my bike but would like to know any tips and tricks to rebuilding the top end on my brother's bike. Im an auto mechanic and the handy man for my mom. I just dont want to dive in and get stuck.


Thanks for any and all help,



Hit up the FAQ section first. I have a good thread in there on the 85/100. Jeekinz has a good on on topend I think. If you can rebuild your 2fitty, the 85 is a cinch. Just learning the one correct step with the KIPS is key. Get the dot lined up. Other than that, it's just your normal 2 stroke.


But if you get stuck, post up, a few of us done this once or twice.

Before you remove the jug, remove the kips valve cover near the pipe. If you have a impact screw driver it is recommended. Those 3 Phillips get heat/ ge we'd up and are hard to remove. Clean that valve. If you run almost any 2t oil besides maxima k2, and you aren't hard on the pipe they gum up pretty good. When re-installing make sure to put the gasket on before reinstalling the linkage control arm. Otherwise you put it all together and when you go to install the cover to find out you have to remove it all to put the gasket on. Did it more than once, and I know about it. Other than that it is an easy 2st rebuild.

Thanks guys. This is a big help. He didnt order the parts this week, so I have a little more time to read and learn. It looks like I'm going to be ordering the parts so I will have a little more time to get the right stuff.


Thanks again,



Need some help quick. Got the new piston on and lubed up but the cylinder WILL NOT slide over it. I squished the rings in as good as I could but still couldnt get the cylinder to slide down over them. Im at bottom dead center. Please help



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