What is this hole?

[Chamelion]

Hi all,

Have my first boat now and have discovered this little hole that isn't mentioned in the outboards user manual.

Note that this isn't my outboard, but she's the same on the exterior, mine's just a few years older -

Cheers

Matt.

[sparkyice]

i beleive thats your lower unit gear lube fill hole. has a hex head plug in it?
on the opposite side of your motor, below the prpoeller level at the top of the scag, there will be a similar hole.
that one is the drain.
when you change your gear lube-which you should do regularly- you'll want to place a pan under the unit, and remove the lower plug.
then remove the fill plug, and when the air rushes in the lube will drain freely.
i let mine sit a few minutes to drain completely, and flush it with a bit of new lube.
then replce the drain plug. and fill with lube til it reaches the top hole-thats also the level indicator, no dipstick here.
be mindful of the fluid that drains out.
if it's milky and slimy, possible seal leaking in water.
if it's dark and smells burnt, possible cooling issue or bearing going bad.
i change mine alot more often than the manuf. suggests. it doesnt take long, and the lube isn't that much money. i like it to look the same coming out as it does going in.
buy a shop manual for your motor. it's well worth the investment.
tight lines,

joe

[Spaniard_King]

its a water pump vent/drain hole most gearcases have a few in them so as when the gearcase is submerged you dont have an airlock.

If you put a set of muffs on and turn the water on you will/should get water comin out that hole.

Oil fill and drain points will have screw heads on them about 12mm wide and they are found above the cav plate and at the bottom of the gear case tubular section

[Noelm]

Spaniard is correct (as usual) did anyone get a spam website come up when you clicked on the image link? I certainly did.

[Outsider1]

Spaniard is correct (as usual) did anyone get a spam website come up when you clicked on the image link? I certainly did.

No, no other website came up, or attempted to pop up for me.

Cheers

Dave

[Noelm]

hhmm just tried it again and all is OK, pretty odd that one!

[Boat Man]

Hi Men,

Spanyid is correct, it is related to the cooling system. It is actually a drain system that allows the water to drain back through in the cavities internal near the vater pump housing....Why you may ask...well not all outboards are manufactured to operate in such mild climates as this brown land of ours.

In the US and europe a motor that is stored for winter in sub zero temperatures can and do crack when the water remaining in any of the cooling passages freezes and expands. mercruiser has a dewatering system as standard on most sterndrives.. however you can't put anti freeze in an outboard as there is no water left inside...

Just a note to sparky ice re gearbox oil... Spot on ion every aspect however an improvement on your proceedure is as follows;

After draining the oil (and flushing as you noted) don't replace the bottom drain hole!!! sound crazy i know.

Insert the tube nozzle into the drain hole and "Pump" the oil upwards into the gearbox. This is guaranteed to purge all air pockets on the way and its much faster. When the oil dribbles from the top hole its full.. replace the top vent plug first (make sure the fibrous seal is in place) this then stops the oil from rushing out the bottom when you remove the tube. Fit the bottom drain plug and you are away...guaranteed to have the exact quantity of gearbox oil..

Also note most of the drain plugs are magnetic, they do this so they pick up and stray metal from the dog clutches in the box. make sure you check and wipe them off. New motors will have a small amount but if you see anything serious might pay to get the gearbox looked at before you do irreperable damage...

Cheers

[Dirtysanchez]

Yeah, that website tried to do a new pop up site, but my pop up blocker thingy stopped it.

Sounds like as usual the guru's on this site have this sorted for you

[Chamelion]

Cheers lads, I figured it would be something like that. I just wanted to make sure there wasn't supposed to be some sort of plug happening there.



Matt.