philly1212
10-02-2010, 08:26 AM
i have a 2001 400ex that is completely stock except for a k&n air filter. I have had the bike for almost a year and have had no problems until lately it started making this squeaking sound. It will only happen after ive been riding for at least an hour and a half then when i really get on it in mostly 3rd and 4th it makes a squeaking sound only when i am on the gas accelerating. Squeaking to me means not enough lubrication so i checked the oil the next day after it squeaked for the first time and it was low. I used 10/40 valvoline atv oil but when i noticed it burning a little i switched to 20/40 valvoline motorcyle oil and it seems to burn a little less but it still makes that squeak sound after about an hour and a half of riding. It doesnt smoke at startup or when riding so im thinking the rings and valve seals should be ok but i dont know. Im really stumpped here. I am about to tear the whole engine apart because i know something is not right and further riding will only worsen the problem. Someone told me it could be my clutch because when it makes the squeak sound i am going through the gears engaging the clutch, but like i said i dont know. If anyone could help id greatly appreciate it.