Mercury mariner 200

[nugent]

Have just stripped down a 1999 model carb job

Any one know what this is in the water ways? Looks like an anti protectant has been pumped through it after build? Yellow ish product protectant I presume


The engine failed due to port side thermostat being bunked up with said stuff,,, I thought it was a piston pin with a missing clip that caused it but the whole one Side of engine has all been nipped on the pistons due to heat,,, this is a very low hr engine,,,
Hence I am thinking this said potion caused said failure , it's well adhered coated where it touches

Any ideas? Do I need to remove it ?

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[Nos4r2]

Silly question, but does it melt if you warm it? I'm wondering if someone's done something really stupid like trying to run it up in oil to keep the waterways from corroding.

[nugent]

Originally Posted by Nos4r2

Silly question, but does it melt if you warm it? I'm wondering if someone's done something really stupid like trying to run it up in oil to keep the waterways from corroding.

Not tried but can do tomoz

I have stripped my fare share of outboards and jet ski lumps and have never in my life seen this nor heard of it
Well strange.

I was informed it sat in a river lots, now thinking may Brits been submerged but there is no corrosion on Steel components and carbs are mint


rob any ideas ?

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[uncle al]

any chance of a decent picture?

[nugent]

Originally Posted by uncle al

any chance of a decent picture?

This do ya







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[nugent]

these may help more ?

[Nos4r2]

Is that a crack I can in the 3rd pic in the post above?

[nugent]

Originally Posted by nugent

these may help more ?

At last good news apparently this is coated from new, obviously every engine I have stripped has done many hrs and this has been worn away hence no coating visible..

So I appear to have a genuine low hr engine,

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[uncle al]

good pics I have seen it in fairly new p/hs but I have never seen it block a thermostate and wreck a p/h it is an inhibiter

[nugent]

Originally Posted by Nos4r2

Is that a crack I can in the 3rd pic in the post above?

Hence the new liner getting dropped in there

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[nugent]

Originally Posted by uncle al

good pics I have seen it in fairly new p/hs but I have never seen it block a thermostate and wreck a p/h it is an inhibiter

Cheers for input Al

Bit of a mystery why it went bang.... I am leaning towards an air leak one side causing it to run lean,,,, as thermostat was not totally bad and I am sure the alarm would of sounded


Defo going through this one with a fine tooth comb, my machinist I'll tell,me if it's iffy casting or not

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[Turbodiesel]

Like uncle says, i have seen that lots of V6 blocks. What do the pistons look like?

[nugent]

one side is 100% fine look bloody new really

tother has drag marks on returns of pistons as if not been lubricated
but tops look normal and rings are free in them
i did notice that one bleed pipe was split on that side,,, this would not cause it surely ?


will post some pics later

[uncle al]

are the failled pistons oily? if not look at the oil pump drive and oil pump, what is the colour of the sparkplugs on the failled side?any air bubbles in the oil pipe to the oil pump/

[nugent]

stuck at work shall investigate later with pics when i go home,

[nugent]

now think the oil drive on crank was the cause of this its looking pretty fecked

pistons showing drag marks

[nugent]

thing is again if oil pump failure surely the alarm would sound also both sides would be k nacked not 1 ?????????

[J.W.W.]

Nugent, Would you be able you take a better (clearer) picture of the crankshaft?
It looks like it has rost marks along the bearing surfaces (condens-water) and a light blue color (heat), but I can't see properly at this pictures.. Also like to see a clear picture of the oil-pump gear and a picture from the other side and the topside of the same piston you posted above. Thanks!
Gr. W.

[roofer]

Looks like lack of oil to me . You should always run a v6 Merc on premix .The oil injection system is crap and prone to failure .

[nugent]

sorry stuck at work will post some clearer pics later,,,,,,,,
defo no rust marks on crankshaft, its lovelly and no bluing any where even on top of rod ends which i striped last night,

the crank oil drive is well shot pics are crap i agree,,

pre mix is good but bloody hard work when filling 400ltrs or so as you need to fill prior to adding oil to know qty required then mix a amount with some fuel there after add it in tank this process has allways worried me,

on a small tank that you know exactly what is req and oil can be added prior to fuelling ensuring a good mix is fine

but yes you know its being oiled if fuel is going down its neck