Gasgas ec300 2006 crank shaft seal help

[dopeman264]

Hi everyone

Ok so I recently bought a 2006 ec 300 the bike did run relatively good, so after a few rides I decided to change the oil, when I drained it only 600ml
Came out so i replaced it with 900ml and it started smoking really bad and burning oil.

I?m guessing the crank seal was already blown and 600ml
Sat below the seal.

After stripping the bike I noticed the seal looked like it had popped out (see pic)

So ordered some new seals and o-ring and installed them as per workshop manual I used fresh 900ml of oil again.

The bike ran great for a couple of hours then started smoking really bad and burning oil.

After stripping it down again it appears the new seal has also popped out, has anyone seen this before or have any idea of what?s happening please

Tia steve