Kx450f oil breather line question

[BLR STS]

The other day who wanted to trade bikes and he asked me to start it up so I did and started reving it upreally hard and oil started coming out of the breather tube. Ive never had this happen to me and dont know what causes this. Can anyone shed some light on this issue for me?

 

[Matt90GT]

more than likely the motor is overfilled with oil or the wrong weight of oil (not allowing to drain back to the bottom of the motor, pooling in the top and out the overflow).

Other causes, piston blow by.

 

[BLR STS]

ive always used 10-40 snythetic and I started it up again and it didnt do it..?

 

[BLR STS]

If I do have blow by to I have to replace the piston?

 

[Matt90GT]

Specs for the 08 say 10w40 1.2L

So check your level next time you do an oil change.

If you have blowby, you more than likely need to at least rering the piston if not replace it and hone the cylinder.