Crank seal leak?

[MuddyArgyle]

2011 ec300. I have been trying to figure out why my bike is running rich (super smoky, some bogging, lots of oil out the pipe). I have replaced the reeds, piston has maybe 20 hours of mostly low revs, and I replaced the crank seals on both sides.

It's still smoky, and on my last ride the clutch started making funny noises. I went to change the oil afterwards and only ~500ml came out when I had put 1000ml in(rekluse clutch cover allows a little more volume) about 5 hours earlier.

So it seems my crank seal replacement attempt was unsuccessful. I am asking if any of you have tips or other advice for installing the wet side seal and the oring that goes inside.

Thanks

[gasgasman]

Did you install the seal with the garter spring facing the transmission oil side?

[Gasser Nate]

Leak down test is your friend here. It may even be the centre case gasket.

[cladoo]

I had the same thing on my 2010 Nambotin. It was the centre case gasket at the top where the intake is. It only sucked tranny oil when I was on the gas!

[motopsycho87]

Remember it's not just the crank seal, behind the primary drove gear there is a collar on the crankshaft, behind that collar is also an o ring that can fail

[gasser]

I had the problem you described after putting together a motor that had been sitting disassembled in a box for two years. Upon reassembly I managed to leave out the o-ring at the water pump seal. The bike would start and run for several hours if you kept the revs up but it would smoke like a freight train. After riding half the oil would be gone from the tranny. Once I put the o-ring back in the bike it ran perfect and quit using tranny oil.

[MuddyArgyle]

Thanks for the advice everyone. I installed the seal having the same way as the old one was. I did install the o ring, but not until after I put in the main seal (I didn't realize that's where it went). I pulled the collar out and then put the oring in, then put it all back together.

I will investigate the center case gasket. I guess a leak down test is the only way to confirm that's the issue? And fixing in guessing involves pulling the motor and splitting the cases?