Motorcycle Repair: Oil Leak on 85 Yamaha FJ1100, crankcase breather, oil seals

Question
Mark,

We are having a hard time finding a leak back by the front sprocket.  We have replaced the countershaft seal and another seal in that area, but after the repair it appears fixed and then starts leaking again.  Oil is coming out from where the wires go up to the oil sending unit.  Do you think it might be the shift oil seals?  I saw that there are about 3 seals listed in the schematic from Yamaha.  Do we need to replace all of them?  Could this be the sending unit?  If so, is it hard to fix?  Could it be the crankcase breather tube? I asked my mechanic and he said that they rarely get obstucted and cause backpressure.  I appreciate any insight.  Thanks.  
Frank

Answer
Hi Frank,

Q:  Do you think it might be the shift oil seals?

A:  It's possible


Q:  I saw that there are about 3 seals listed in the schematic from Yamaha. Do we need to replace all of them?

A:  Ideally, you should replace all seals.


Q:  Could this be the sending unit? If so, is it hard to fix? Could it be the crankcase breather tube?

A: I doubt it, but it's possible.


Try using Dr. Scholl's Foot Powder Spray to help find minute oil leaks. The powder is pure white. Spray it on suspected areas. Oil seeps through as a dark brown stain. Clean up is easy- wipe away.

Respectfully,
Mark Shively