Has my head gasket gone?

[brandenjg]

Hi everyone, after noticing my 15hp mercury was running smokier than normal I gave her a once over.

 Checked oil level and found the oil was overflowing, watery and cloudy. Not good.

Then checked the spark plugs to find them thick black. Not good.

 So I got my brother to have a look and he's told me it seems like the head gaskets gone.

 Does anyone know an average price for a head gasket replacement on a 15hp mercury. Also any recommendations for mechanics on the southern broads to take it to.

Great start to the season

thanks in advance Branden

[Guest]

The best way to make sure would be a cheap compression tester, via each plug hole, and a partial strip down, (best to make sure first, it could be a cracked head instead).

You've always seemed like a handy chap Branden, why not have a go at replacing it yourself, to save the labour costs ? 

Much simpler than a car head gasket change. There's plenty of youtube vids on the subject. The only specialist tool would be a torque wrench, quite handy to have for cars and bikes too.

https://www.google.co.uk/search?q=mercury+15hp+outboard+head+gasket&ie=utf-8&oe=utf-8&gws_rd=cr&ei=1yHTVujIE8PwUMHktvgD

[brandenjg]

Hi strow my first thought was doing it myself as screw fix have the tester for £20. I'm sure I'd be able to replace the gasket easy enough but since moving house I don't have a space to strip the engine :/ 

[JawsOrca]

Hi Branden,

I guess it's 4 stroke?

If there is emulsification in the oil then it would be a fair indication that the gaskets gone or an oil seal has given up.  Did you winterise it correctly? What colour is the smoke? Does it get hot? Is it pumping water? 

Sadly as I think you suspect outboard repairs aren't cheap if done by dealers.  Andy at Kingfisher (Freedom) is close by, you could try Mark (MBA marine), (I don't think Graham at maffetts does outboards) or if you can get it in a car Russell Marine (South Walsham) are outboard specialist or boulters at horning. It's certainly worth trying to do yourself though.. are you sure your other half won't let you borrow the living room floor for a couple of evenings

Good luck.

[Guest]

23 minutes ago, JawsOrca said:

 Did you winterise it correctly?

How would you specifically "winterise" a raw water cooled outboard ?

(other than tilting it out of the water).....

[JawsOrca]

2 minutes ago, Strowager said:

How would you specifically "winterise" a raw water cooled outboard ?

(other than tilting it out of the water).....

You've answered your own question there....

[Guest]

12 minutes ago, JawsOrca said:

You've answered your own question there....

It was just that word"winterise".

It made it sound like a vital sequence of steps like in an inboard powered engine..........

[grendel]

I had a volvo 340 head gasket change down to 35 minutes bt the roadside when I had a warped head on it, a complete engine change was 1 1/2 hours.

[Maxwellian]

Does Andy at Freedom (Kingfisher) do them?

[Guest]

45 minutes ago, grendel said:

I had a volvo 340 head gasket change down to 35 minutes bt the roadside when I had a warped head on it, a complete engine change was 1 1/2 hours.

It took me a bit longer to refurb the heads and manifolds on my Volvo Penta V6.

A very satisfying job though, quite simple with the right tools and workshop manual.

 

 

[brandenjg]

Would this be the right gasket and service kit for my outboard. I'm fairly useless at matching parts without being able to see them.

branden

 

[brandenjg]

Ended up doing a full engine strip down service and rebuild. One part now needs replacing but can't find the part in the uk. Can anyone find or source one in the uk? Link to the part is here http://www.marineengine.com/newparts/part_details.php?pnum=MER27-854617

Thanks in advance everyone. Branden

[FairTmiddlin]

In Germany

https://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.hafner-bootszubehoer.de/product_info.php/info/p138317_gasket--27-854617.html&prev=search

[Viking23]

6 hours ago, brandenjg said:

Ended up doing a full engine strip down service and rebuild. One part now needs replacing but can't find the part in the uk. Can anyone find or source one in the uk? Link to the part is here http://www.marineengine.com/newparts/part_details.php?pnum=MER27-854617

Thanks in advance everyone. Branden

What does the gasket do, where is it placed?

In some situations, you can buy gasket sheet in various thicknesses and cut your own.

Might be an option.

 

[Oddfellow]

On 28/02/2016 at 5:51 PM, Strowager said:

How would you specifically "winterise" a raw water cooled outboard ?

(other than tilting it out of the water).....

By allowing all the water to run out of it and possibly buy running anti-freeze through as you would an inboard. By drying exposed aluminium, draining the carb an possibly even by fogging the engine with fogging oil. All depends how far you want to go.

 

[Oddfellow]

Yes. We do a lot of outboards. Just completed one for one of the Fairhaven Water Gardens trip boats (video on our Kingfisher Facebook page.)

You cannot buy your own head gasket and cut it out/down whatever as you may be able to do with some others. Head gaskets are specialist products designed to take large pressures and contain explosions. 

Branden's situation doesn't sound good. A head gasket generally blows for a reason and in an outboard, its often bad news.

A compression test is probably pointless. There's likely no way the water can get into the oil without either a crack in the block and/or head or a blown gasket. A compression tester will not tell you which this is so it would have to have the head taken off it anyway and it will need a new gasket if it can go back together. 

Don't just buy a gasket. All these engine parts are located using the serial number. There may be differences between one 10hp model from 2009 and the next, seemingly identical model from 2010 - you may easily waste your money. 

Bring it in to us at Kingfisher and we can take a look for you or you can take the head off yourself. Be careful with the timing, these are overhead cam driven so removal of the head without proper knowledge of how to set the timing could easily destroy the engine if you reassemble it wrong. 

[Guest]

4 minutes ago, FreedomBoatingHols said:

By allowing all the water to run out of it and possibly buy running anti-freeze through as you would an inboard. By drying exposed aluminium, draining the carb an possibly even by fogging the engine with fogging oil. All depends how far you want to go.

My reply was in answer to Alan's (JawsOrca) "did you Winterise it correctly".

It was in reference to Branden's OB, left on the back of the boat on a mooring, still afloat.

Making it difficult to fit an intake muff on the leg to draw anti-freeze in, or "drying exposed aluminum".

I quite agree with the fogging oil and draining of the carb, though that wouldn't be specific to an outboard.

Draining the carb by letting the engine run on after closing the fuel tap is good practice before leaving the boat anyway, at any time of year. Stale lead-free petrol gums up the works much quicker these days.

[Oddfellow]

If the engine can be tilted, muffs can be fitted. 

[Guest]

5 minutes ago, FreedomBoatingHols said:

A head gasket generally blows for a reason and in an outboard, its often bad news.

The part number that Branden has given isn't the head gasket Andy.

Although that's the title of the thread, the part number that Branden has shown is 27-854617, which doesn't look like the head gasket in this diagram, (on a 4 stroke engine).

https://www.marinepartssupply.com/book/9994/311668/    (number 8 in the exploded diagram).

It appears to be part of the driveshaft housing.

 

 

 

[brandenjg]

4 hours ago, Viking23 said:

What does the gasket do, where is it placed?

In some situations, you can buy gasket sheet in various thicknesses and cut your own.

Might be an option.

 

There's a plate with the exhaust vent pipe in the mid section of the outboard. The gasket is the seal for the plate. It was completely soaked with water and had bubbled and split. I think making a gasket will be the only way to do it if I can find the right material.

 

[brandenjg]

7 is the plate, 8 is the gasket which has gone. Branden

[Oddfellow]

What you describe and show, Branden, is not the head gasket. All gaskets for this engine should be purchasable. 

The head gasket is between the top of the pistons and the cylinder head at the top of the engine under the drive belt.

I feel it is VERY unlikely that what you show here is anything to do with having water in the oil. In general, the only way that you will get water in the oil is for the head gasket to blow or for there to be a crack in the block and or the cylinder head. Any fault you find in the area depicted in the exploded diagram is likely coincidental or a knock-on from the real problem. 

 

 

 

[Oddfellow]

https://www.marinepartssupply.com/book/9994/311663/

Part 8 in this image is the head gasket. You'd probably best get a full gasket set, as none of the existing gaskets would be reusable when you stripped this down. 

 

 

[brandenjg]

Just to clarify I've replaced the Head Gasket already so the original thread is resolved. But whilst I had the outboard out of water I checked the whole engine then found the gasket for the mid section exhaust needs replacing.

I thought it best to ask advice in this thread about the new part that needs replacing.

[Guest]

1 hour ago, brandenjg said:

There's a plate with the exhaust vent pipe in the mid section of the outboard. The gasket is the seal for the plate. It was completely soaked with water and had bubbled and split. I think making a gasket will be the only way to do it if I can find the right material.

Yes, as Viking23 suggested also, if it were me I'd probably just make a new gasket.

Although gasket sets are usually fairly cost-effective, individual gaskets can be well over-priced for what they are.

I've always found plenty of gasket material on Ebay, which then becomes good reserves for any future needs.

http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2060353.m570.l1313.TR0.TRC0.H0.Xgasket+material.TRS0&_nkw=gasket+material&_sacat=0

Probably best to get a cheap hollow punch set as well, to make the small holes as neat as possible.

http://www.ebay.co.uk/itm/6Pc-HOLLOW-PUNCH-SET-Gasket-Hole-Punching-Leather-Belt-Wood-Paper-Plastic-H1700-/151871108134?hash=item235c393426:g:LtUAAOSwAYtWNlHe

There's plenty of Internet guides and youtube videos on the simple technique of making them.

https://www.google.co.uk/search?q=making+gaskets&ie=utf-8&oe=utf-8&gws_rd=cr&ei=_8DzVtPhG8LJPfSMoNAO