Toss the synthetic and put good 10W40 back in. The theory being, you shouldn't run syn. till you have 6 or 7 thousand miles on the bike. Yeah I'll probably get flamed from those that have the opposite view, but I have seen too many have engine and gasket problems from using syn. too soon. Ther have been several also have the same issue you have, leaky gaskets and seals after changing over to syn. going back to standard oil all but cured the issue. You may want to check that cover, when you have it off again and make sure the surface is flat and true. You could have an issue with the surface causing it to slightly open up after the engine gets hot.

 

Take the cover to a machine shop and have them surface the cover, it may have a defect that you cannot see or feel.

I have been running Mobil 1 since 1500 miles or so - no issues.

Sean

 

Is it coming from the cover or out of the weep hole for the water pump? The oil seal might be trashed.

 

Here's the deal. I had the whole cover replaced recently($180) Its brand new kawasaki and all. I have taken out the oil synthetic and put in 20W 50. Still leaks. I just took it to casa grande(60miles round trip) about 20 minutes ago and its got a good 10 to 15 good size drips under it. I have tried about every thing you can imagine. It is not leaking from the "weap" hole directly under the water pump. My bad. Its leaking from the round part of the case under the water pump. you may have to remove skid plate to see it. Do the cork(factory) gaskets leak for any one else... I guess i am going on number 6 for how many times i have removed the case. ha ha. One good thing. I have it down to about 6 minutes : ) Thanks for the help guys.

 

Have you used Black RTV silicone sealant on the gasket surface? Might be your last resort, but usually works on everything that leaks. The secret to it is to let it set up overnight before starting the motor.

 

not tried the black rtv. Thats what we used at toyota for valve cover gaskets and what not. Ill try it next. thanks dxklr