Lower unit leak

[TownsendsFJR1300]

I guess the actual Yamaha SHOP manual on how to test it (as posted previously from the manual) should be simply ignored, shredded.

Heck they only designed the engine. What do they (Yamaha) know about testing a LU???

If Yamaha wanted it to be tested using vacuum, it'd be posted..

Note, I watched a Yamaha Master tech pressure test my LU, 10 PSI, for 10 seconds (after a drive shaft seal replacement) THREE and half years ago. NO other tests.. LU oil is still g0lden after each year (changed yearly)..



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[brielly1]

Thanks for all the responses guys. I'm feeling pretty confident that the seals are good.

[rodbolt17]

kinda like the dumb advice about drilling the seal and not pulling the carrier and doing it right.
one reads all kinds of stupid stuff on the net.

[scofflaw]

If the carrier o ring doesn't have a leak, why fix what's not broke ? Big slide hammer, special fitting, blue wrench, most don't have those things laying about.

[walleye1]

Pull the carrier, do it rite. Should have them seals centered at depth. Unless u want to do it over at getting payed flat rate.

[pstephens46]

I just confirmed something I noticed a time or two before. I installed brand new gaskets on the drain and top screw after the lower unit oil change a month ago.
Tightened as I normally do. Very loose today when I picked up boat from the storage yard. So I may have a bit of water in oil from the past trip of 50 plus miles. Going to run it a few more times and change it again.

[TownsendsFJR1300]

I just confirmed something I noticed a time or two before. I installed brand new gaskets on the drain and top screw after the lower unit oil change a month ago.
Tightened as I normally do. Very loose today when I picked up boat from the storage yard. So I may have a bit of water in oil from the past trip of 50 plus miles. Going to run it a few more times and change it again.

Mine as well loosens up after changing...Not as bad as your description, but after the days run (right after the LU oil change), I re-check AND tighten.

The torque spec (which I don't usually follow for these drain/fills), is, with a torque wrench, is amazingly tight!.

Much tighter than you would do by hand...(at least for me and apparently for you!). Never had ANY water intrusion what so ever...

[pstephens46]

Mine as well loosens up after changing...Not as bad as your description, but after the days run (right after the LU oil change), I re-check AND tighten.

The torque spec (which I don't usually follow for these drain/fills), is, with a torque wrench, is amazingly tight!.

Much tighter than you would do by hand...(at least for me and apparently for you!). Never had ANY water intrusion what so ever...

Damn gasket is the consistency of wood. Seems as it might absorb some oil after a period and then you can compress a bit more. Who know?

[TownsendsFJR1300]

Damn gasket is the consistency of wood. Seems as it might absorb some oil after a period and then you can compress a bit more. Who know?

Yepper, it definitely loosens up.. Think about the guy that has the SHOP do it. AND, it never gets re-snugged...