Does anyone know if there is supposed to be engine oil in the side of the motor where the flywheel and starter is on a 400EX?

This might explain why my bike is viberating so bad. The Crank Bearing on that side could be bad and the seal is broke allowing oil to get over there. Could a little tiny bit of sand get down in the crank and ruin a bearing and seal and sneak past the rings without any sign of damage to the piston or cyclinder wall???

Anyone ever have vibration problems??

Help! My 400EX is torn apart trying to find out what is damaged causing the bike to viberate so badly. Piston and rings are good, cam looks good. Any suggestions??? Please!!

Thanks....