yup, make sure you have spare circlips. Those things fly when they come off. piiiiiiiiiiiiiiiiing!
I'm actually thinking of swapping mine back to stock. After the change over, the entire cover is actually BEHIND the frame and only the extended woodcraft slider goes beyond the frame making the mod not very effective for its intent. It also raises the sight glass for oil on the 2nd gen bikes. This makes it very easy to overfill. Once that is done, it shoots oil up into your airbox under load. Even more so, it can blow off the breather tube depending on the age of the rubber of the tube and the hose clips. It make one helluva mess for me and almost took out my first race weekend.
Now, when I change the oil, I make sure I fill the oil filter until it is good and full. Then from there, I had to carefully measure out 2300ml to make sure that I did not overfill the engine.
On the plus side, when you change your clutch pack, you don't lose much oil at all with the change. Since I change it once per year, it's not that big of a bonus for me, but not seeing my oil level feels like a massive faux pas to me. Luckily, I change it after every race weekend, so I know that the levels are now good, so the sight glass doesn't really matter in that respect. It just feels weird to look at it and not know where it's at. It also caused me some grief at a US track where they insisted the bike needed to have proper oil in the sight glass...It took me 20 minutes to explain to the head tech, and provide pictures to convince them that I was okay to have it like that.
I'm only keeping it on to be able to compete in Blair's contingency program.