Blown Crankshaft Seal - 2017 Yamaha F115

[japankra]

ANYONE have this issue with a 90 -115 hp? Looking for a root cause for this issue?? Authorized Yamaha repair places (4 in total) have no clue for the cause. Seems high crank case pressure at near WOT, but why??. Any ideas/assistance is greatly appreciated. Thanks

 

[boscoe]

Blow by from worn rings can result in excessive pressure build up within a crank case. As can a clogged vent line from the crank case.

 

[japankra]

Blow by from worn rings can result in excessive pressure build up within a crank case. As can a clogged vent line from the crank case.

I will check the vent line. Need to find a schematic. Thxs for the reply.