power valve over flow hose /black oil?

[ukracer]

Hi guys
03 yz 125 i have black oily substance dripping out of over flow hose from power valve i think is this normal or is jetting wrong , also i do get smoke coming out of it sometimes as well is this normal.
Any advice would be great
Cheers

 

[marcusgunby]

It is normal to get a small amount of goo and smoke out of that pipe as it is a vent for the pc, however if its excessive you need to jet it leaner.See www.eric-gorr.com for the jetitng guide.