It is a design flaw in the engine that actually goes back to the ZX 1400 in 2006. There is too much surface area on the seal (flat face) and not enough pressure (one, the other or both as you like) to make an effective seal.
Unfortunately a dealer is limited to what they can do- they must use factory parts and follow the factory method.
There are a couple of methods to address this issue that seem to work pretty well; one is to put a thin bead of RTV sealant under the seal in the groove in the valve cover, assemble the cover onto the engine loosely and after a couple of hours, tighten it fully. Another method is to put thicker washers, or additional washers under the heads of the valve cover screws. Both accomplish the same thing- to put more pressure onto the sealing surface. We have to be careful doing these things though as too much pressure and something will break, most likely the valve cover itself will crack.
A quick Google search should turn up lots of detailed information on this problem.
Brian
2008 Connie.
The first time it was leaking from the front left corner of the valve cover. It was replaced under the GTPP coverage. I re-up'd the coverage for 3 more years over the summer and I am happy I did it because the bike has started to leak oil again from the same area.
Why? Possible uneven mating surfaces between the valve cover and top of the head? For you guys that have had the valve cover leak, has it returned again? Leaking from the same area?
