The SB8 is a vertical cylinder engine, the YSB is a horizontal cylinder engine.. not the same.. Sailor27 is asking about the gear case cover, not the flywheel housing. The gear case cover is right behind the harmonic balancer, like Bill says.. The gear case houses the governor as well as the cam end and the injector pump. Sailor27, the hang up is most likely the cam that drives the fuel injector and/or the hand crank stub. That stuff is critical to the engine running and has to be put back EXACTLY as it was. The "fuel cam" that drives the injector pump is right behind the hand crank stub that is just above and left of the dampener pulley. It rides on but is not integral to the camshaft. I am not familiar with the SB8 but based on the construction of other Yanmars, it looks like the set screw in the end of the hand crank stub and then the stub has to be removed before the cover will come off. There may be more stuff that has to be removed, and I would recommend you get a manual before going forward. The manual will show which parts are injection critical and will show the correct assembly. (most of the time).. Good luck with it !