Out board Advice

[Blownlc]

Hi All,

I recently noticed oil leaking from behind the prop on my mercury 50hp outboard. I'm wondering if anyone has experience with repairing outboard motors.

My suspicion is that the gear box seal is leaking. Correct?

If so is replacing as simple as the following:

-Undo prop nut and remove prop.
-Use slide hammer to remove retaining disk.
-Use slide hammer again to remove prop shaft centring mount (if thats what its called).

Is it then as simple to just remove the seal and replace it with a new one and reverse the above process?

Any advise is greatly appreciated!

Thanks

Stu

[97_gq_lwb]

You can usually find manuals cheap on ebay or through google.
http://forums.iboats.com/showthread.php?t=309079

If the seals let it suck water in it might be a good idea to flush it out.

[Blownlc]

Thanks for the link. Tried downloading the one I need but the computer can't recognise the format for some reason.
I use it in fresh water only so it shouldn't need a flush.

[97_gq_lwb]

You might need winrar

[Rip'n'Shred]

I have no idea on outboards, never touched them, recently become owner of one though.

I suspect your right in just replacing seal, although I imagine the setup would be the shaft the prop is bolted to, supported by two bearings, with a gear on a spline at the end, inside the housing.

It is possible one of the bearings is stuffed, causing the seal to leak or worst still, the seal leaked and stuffed both the bearings. Either possible.

I guess you'll have to pull it apart and let us all know.

Pics are priceless! ;)

[Blownlc]

You can usually find manuals cheap on ebay or through google.
http://forums.iboats.com/showthread.php?t=309079

If the seals let it suck water in it might be a good idea to flush it out.


Ok so I now know what you mean!!! I removed the lower leg to find the this!

Pretty certain its not suppose to look like that! Water is definitely passing somewhere.

[Blownlc]

I tried gently with a slide hammer to remove the prop shaft cradle, but it didn't budge so I didn't want to force it. So I thought I would remove the lower arm to get a better look at it.

I believe the below shots are how it is suppose to look when removed. Except for the broken rubber which I'm not sure the purpose of.

Any ideas on the whole think any one?

[97_gq_lwb]

Definetely looks like gear oil everywhere i'd be doing the whole gearbox could be the seal under the water pump.
But flush it all out pull it right down and clean all the water out and check the shafts for wear .

[Blownlc]

Do you have any idea how to remove the prop shaft and gears.

It's obvious I'v ever worked on an out board before ey?! It's actually my first boat, haven't had it long.

[my third 256]

this might help not your motor but will give you some idear
http://www.youtube.com/watch?v=ttNSaEyC_UE
stephen

[ReefMagnet]

I've had to do the same thing once many years to a 55hp Evinrude that picked up fishing line around the prop first time out after buying it. The gearbox itself is easy enough to disassemble if you have the manual as they are pretty simple all things considered. The worst bit was pulling the bearing carrier from the housing thanks to normal everyday corrosion. I made a special puller to pull the carrier, but it wouldn't budge. I asked some outboard mechs and they said hit it with heat - LPG - which I did (enough to start burning the paint) and it still wouldn't budge. In the end I brought home the ute from work with Oxy-Acetylene on board and the biggest blowtorch I could get my hands on and heated it with this. Amazingly, it took probably less then 20 seconds and I heard a slight "click" sound. Cut the heat, yanked on the puller and it came off without a whimper. It seems it is the thermal shock between the housing and carrier that breaks it free, not just the heating so much.

The other thing I'd suggest is get the full service kit while you got it apart, especially in the state it looks to be in. That will also include the drive shaft seal and O-rings and maybe even bearings (can't remember if they come with it). Oh, and replace the water pump impeller and housing while you are at it.

[Blownlc]

this might help not your motor but will give you some idear
http://www.youtube.com/watch?v=ttNSaEyC_UE
stephen

That is actually quite useful, thanks mate. I think the merc is a slightly different set up, but it gives me a good indication of how the components work. Cheers!

[Blownlc]

Reef magnet: I think you have a good point about the service kit. While its off I might as well do the lot. As for the water pump impeller it is in very good condition. The previous owner told me that his mechanic changed it every service, by the looks of it he's telling the truth.

As for pulling the oxy out I might use that as a last resort.:sterb032::cool:

I'll post progress shots as I go. This could end up being useful to someone else.

[Blownlc]

Ok. So I finally made it down to the marine shop today. I spoke to a gentleman who was very helpful, I took the pictures in and showed him what it all looked like. He sat me down and took me through a break down of the gear box components.

Prior to going to see him he instructed me to drain the gear box oil out. I did so, and whilst going through the components break down I showed him images of the gear box oil. I didn't think it was very cloudy and neither did he. We came to the conclusion that that the oil that I first noticed dripping out from behind the prop was unburnt two stroke oil :icon_bonk: and that the oil/sludge could be a result of the exhaust seal.

He has told me to fill the gear box back up with oil and take the boat out for a bit and pull it apart again to see if it leaks the gear box oil. And also drain the oil to see if it is cloudy. If not all is good. If so,,, full over haul. Though he seems to think it will be ok.

So for now I happy that I'm and idiot.