Engine Vibration

[Shawn_guru]

Well I'm not sure whats going on with my 400ex but when I have been riding it lately it's been making a strange vibration , almost like something in rubbing on the left hand side of the engine by the crankshaft, could anyone tell me what's going on?

[cals400ex]

i would just go through and tighten up all the bolts that you can get to around the bike. i assume your chain is not rubbing down there?

[Shawn_guru]

nope its not the chain, everything it tight, it sounds as if something is going on inside the engine .... I'm really not sure what to do I don't want to keep riding it and maybe wreck the engine

[KASCHAK]

i had the same problem and still do. it was my skid plates. there not snug on there or something you need to take off the brackets and grind them down a little so it holds the skids harder. or just put some sillicone there or somehitng thats all i did.