Can anyone advise

[TUFTY]

Hi

I ran my Yamaha 60 up in a barrel of water for about 10 minutes it appeared to run fine.

This was the first run since laying up over a year ago.

later there was a significant amount of oil floating on the water surface. It smells like transmission oil.

I didn't run the engine in gear at all.

I was intending to change the gear oil but am now unsure if there is a leak.

Is there some form of oil seal behind the propellor which may need attention?


Thanks

Tufty

[Nos4r2]

Maybe-drop the gear oil and see if it's emulsified or water runs out.

[chewy]

I'd put money on this is oil that has come out of the exhuast and there is nothing to worry about.
It won't do any harm to see what the gearbox oil is like as its easy to do.

[Nos4r2]

Originally Posted by chewy

I'd put money on this is oil that has come out of the exhuast and there is nothing to worry about.
It won't do any harm to see what the gearbox oil is like as its easy to do.

I thought that, but it doesn't usually smell like transmission oil.

[chewy]

Originally Posted by Nos4r2

I thought that, but it doesn't usually smell like transmission oil.

Very true.
Not sure if he's ever ran an engine up in a barrel as it might shock some people how much fuel and oil comes out.

[Nos4r2]

Originally Posted by chewy

Very true.
Not sure if he's ever ran an engine up in a barrel as it might shock some people how much fuel and oil comes out.

Fair point.

I love the smell of 2 stroke in the morning. Smells like....victory

[chewy]

When I lived at my parents we had a shed full of creosoted wood and a load of petrol and two stroke oil, smelt lovely!
Can't beat a few revs on the warm up lever!

[TUFTY]

Originally Posted by chewy

Very true.
Not sure if he's ever ran an engine up in a barrel as it might shock some people how much fuel and oil comes out.

It may be just oil from the exhaust, I have ordered some gear oil and a pump so will
drop the gearbox oil in the week and see what occurs.

Thanks for your help, I will update when I've done the oil change.

Cheers

Tufty

[TUFTY]

Originally Posted by TUFTY

It may be just oil from the exhaust, I have ordered some gear oil and a pump so will
drop the gearbox oil in the week and see what occurs.

Thanks for your help, I will update when I've done the oil change.

Cheers

Tufty

I drained the gearbox today and am not too pleased.

After a initial dribble of clear water a large quantity of "runny green snot" drained slowly out!!!!

I guess this is the oil emulsified with water which has got into the gear casing.

What should I do next?

[jyasaki]

Either replace the gear oil and retest, or have a shop do a pressure test on it (pump the cavity to a couple of pounds over ambient pressure, and see if it holds the pressure or leaks down.)

I would strongly suggest the latter.

jky

[Nos4r2]

Originally Posted by jyasaki

I would strongly suggest the latter.

So would I.

[TUFTY]

Assuming the pressure test fails, what does the repair involve in terms of spares cost and degree of engine dismantling?

Thanks for your continued advice


Paul

[Nos4r2]

Originally Posted by TUFTY

Assuming the pressure test fails, what does the repair involve in terms of spares cost and degree of engine dismantling?

Thanks for your continued advice


Paul

Depends which seal is gone. It might be cheaper to change the lower unit for another 2nd hand one,or it might be a 45 minute job.

[TUFTY]

I am going to get some "cheap" transmission oil and fill the gear case then run the engine again and see if water gets in.

Should both the top and bottom screw plugs have fibre washers ?

I found the lower one has a fibre washer but the upper one has a copper washer and O ring.
Is this correct?


Thanks again

Paul

[Nos4r2]

Originally Posted by TUFTY

I am going to get some "cheap" transmission oil and fill the gear case then run the engine again and see if water gets in.

Should both the top and bottom screw plugs have fibre washers ?

I found the lower one has a fibre washer but the upper one has a copper washer and O ring.
Is this correct?


Thanks again

Paul

Either works, as long as done up right. It's supposed to be a fibre washer on both plugs though,so it's a small possibility if the copper washer had been reused that your leak was round it.Unlikely though in the quantities you described,and there'd probably be no clear water in there.
Replace the fibre washers every time you change the gear oil.

If I were to hazard a guess, I'd say it was probably the propshaft seal gone.


You'll need to run it up on muffs with the 'cheap' oil in first then drain it to get rid of the remains of the emulsified crap first (There WILL be some in there still)or you won't be able to tell. It also means if you've got clear water or really bad emulsification in there after running on muffs it's the driveshaft seal that's had it.

[Downhilldai]

Originally Posted by Nos4r2

...It also means if you've got clear water or really bad emulsification in there after running on muffs it's the driveshaft seal that's had it.

[TUFTY]

Good advice, I will run up on muffs (that will please the neighbours!!!)
and see what happens.

I suspect the propshaft seal as well.

I will post the outcome later.

Thanks

Paul

[Nos4r2]

Originally Posted by TUFTY

Good advice, I will run up on muffs (that will please the neighbours!!!)
and see what happens.

I suspect the propshaft seal as well.

I will post the outcome later.

Thanks

Paul

If you suspect the propshaft seal and it's bad enough you can smell it, make sure anywhere that oil can spray is covered. It'll blow from the exhaust, plus be sprayed everywhere by the prop.

[TUFTY]

Ran the engine up on muffs this morning no oil spraying from exhaust.

Dropped the oil and it is milky with water so I suspect the drive shaft seal.

Also there was a small quantity of oily goo that came out of the hole on the leading face of the leg at cavitation place level.

What do you think?

Thanks

Paul

[Downhilldai]

Drive shaft seal. Drop the leg and remove the water pump.