Rattling Noise

[Paul400ex2002]

When my 400ex is at about 1/2 throttle, or in "mid-range" i hear a rattling noise coming from i believe my valves or something in that area. It only does it in the midrange, but in low- and top-end it doesn't do it. I checked my valves this morning, and adjusted them correctly but it still does it. Anyone have any idea what is wrong?

Thx.

[02exchic]

Is it more like a pinging noise??? Are you running supreme gas???

I've never had any problems (knock on wood) Don't really know what to tell ya. Hopefully somone here will have a solution for ya.

[redrider ex]

i have a buddy that has a 250x and his done that and it ended up being the timing chain

[Leo]

what are you running for fuel (what octane?)..

also what are your mods / jetting?

it sounds like you are describing pre-detonation to me (NOT a good thing)..

Leo

[Houser Cannondale]

could be a cam chain especially if its an older motor.

[440exnacsracer]

do you have a full body skid? my skid makes mine rattle just a little, only in the midrange like your saying. if so, take it off and see. lata

[Paul400ex2002]

Yea it was the chassis skid, only does it in like a 100-200 rpm range i'm gonna take some rubber and stick in there eventually, for now i bent it down a bit with some plyers.