Hey guys in new on here so to start I'll go ahead and say I'm not a genius when it comes to this stuff. Here's my problem. Buddy's dad has a 1990 kx 125. On the exhaust side of the bike, there's some rod coming out of the bottom end. Has a black rubber sleeve over it. Has a little thing that pushes in and out of the top end near the head cover. Makes some little things spin when u pull it in and out when looking under the head cover. Well anyway I took the head cover off and then went to take the top end cylinder off. I went to try to remove a bolt on the top of that little rod bc it needed to be removed to take the cylinder off and when I did it snapped off. We are putting a new piston and rings in it and that's why I was taking it apart but anyway it snapped the bolt off that goes into the top of the little rod that was under the rubber black thing. I have no clue what it is and desperately need to know bc we have to fix it lol. Any help would be GREATLY appreciated. Thanks guys, -Cody

 

Look into a manual if ya can. Sounds like the exhaust valve actuator/rod. Also hit up your favorite parts fiche for a better description.

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