Home › Forum › Ask A Member › More on the 56 15Hp › Re: More on the 56 15Hp
I don’t like to run pressure up on small motors when looking for seal leaks. Can actually cause them to seal? I test at about 5 lbs for seal leaks then higher for spaghetti seal leaks, etc. Might go as high as 15 lbs. The gearcase is either sealed or it’s not. I would rather find it than put it back on the motor (especially 5.5/7.5)!
On big motors it depends on what’s going on. Those high HP units get hot. Poor lubes don’t tolerate heat/pressure well. Might see as high as 30 lbs, but the gearcase won’t last there. If the gearcase is blown then you get to find out when you remove the plug. If I start to loosen a plug (usually top plug) & it farts on me I tighten it back up. She is done. Nothing to rebuild anyway when they blow. Case is warped & she is junk! One bath in metal & burnt gear lube is all you need to learn your lesson.
OMC/BRP units only. I understand Merc has a blow off system around their shift rod seal. Yamaha may have the same thing. The new G2 has a gearcase reservoir. Not sure how that works, but gives extra oil. Older models only had 33 ozs of fluid/lube. The life of those high performance gearcases is lube changes.
Dan in TN