Motor warning tone!

[andrew_nagel]

Andrew, the cooling system is completely separate from the oil system, the thermostat sits only in the cooling system, if you have got water into the oil are you sure the head gasket is ok?

Thanks Ian . That was my first and big worry when the dip stick was pulled and showed milky motor oil. However the digital fault read out pointed at excessive cooling which is usually caused by a thermostat broken in the fully open position which mine was. I've since learned this causes condensation on the inner motor surfaces that never get to warm up due to over-cooling.

https://www.boats.net/blog/diagnosing/b ... thermostat

So a new thermostat has been fitted, and it'll get a few oil flush cycles to see what happens. If that doesn't fix the problem it'll be on to more major work like gasket and cylinder head checking. I hope it doesn't go that far...

That’s interesting Andrew, fingers crossed buddy

Cheers Ian.

[Cod]

Andrew, let us know how it pans out please.

Interesting face.

[Cyprio]

That was an interesting find Andrew.
I guess with all modern tech that goes on with engines these days,
we forget how things used to be. When I started my apprenticeship
in The motor trade, the dealership was Volvo and Vauxhall.
When the old Bids came in for a service you could tell which cars were theirs
as the engines always had white Sludge build up in the rocker covers,
Same as; the engines did not get hot enough likewise excess condensation
Mixing with the oil. ( also they were Chevette's or 340DL's )

Very rarely see it now as most have a better crank case ventilation system, which reduces emissions but also non maintenance head configurations of better design.

Hope all works out for you

[andrew_nagel]

Thanks Paul and Cyprio. It's all new to me - never experienced water in the oil on any of my motors before. I'll let you know how it pans out.

[Will Smith]

All the talk in this thread has made me think maybe its time I looked into replacing the thermostat on mine as well Andrew, 12 years old now my 50 and has never had a new thermostat fitted, is there a recommended time interval for renewal ?
I will check out my manual tomorrow and see what it says, better be safe than sorry.

Will.

[andrew_nagel]

Aye Will... I also have a Yam 40 that I've had from new and is serviced without fail every year. Never missed beat but I know it's never had a thermostat replacement. I'll be pulling it out to check it.

[DavyMc]

I would just replace it for peace of mind Will. Last year bought a new to me boat with engine, gave the engine an oil change and quick look over. Used for few months and then trolling one day an alarm goes off gave me a bloody fright, next besides the constant buzzing the engines gone into limp mode all new fun and games to me bloody technology!
Long story short helped by google and various engine pages it was narrowed down to either a dodgy heat sensor, poor circulation in cooling system or a restriction somewhere. Cleaned up the sensors and flushed the system, then replaced impeller and thermostat. Something worked but because of all the changes done don’t know what it actually was.

Back to a strict schedule of maintenance instead of 5 grand for a replacement

[Cod]

Checking the operation of the thermostat is part of the annual inspection, some high power Yamaha’s have two. Remove the thermostat from housing, put thermostat in a old saucepan of water, heat up with a thermometer in the pan and note the temperature of the water when the Thermostat opens. Compare with manufacturers specifications, change if required.

[andrew_nagel]

Update... the motor has had a new Yamaha thermostat and 4 oil flushes and filters, before filling for a fifth time. Each time the motor was started up on the muffs to let it heat up with the cooling system running. By the fourth flush the oil was running clear of any water. Having taken Carl's advice to find a cheap oil of the same spec for flushing, it was then drained of this and Yamaha oil added for it to run on again when out fishing. The alarm tone doesn't sound any longer and there's no warning icon showing on the digital tach. I'll take it out on a session and check the oil afterwards. For now it appears that the fault was correctly diagnosed as a dicky thermostat and excessive internal condensation build up. Phew!

Now just to head out cod bothering...

IMG_0686.jpeg

[Will Smith]

Pleased to hear that, I bet you are relived Andrew, well done, fingers crossed that's the job sorted now.

Will

[Cod]

Well done Andrew.

Good result face.

[andrew_nagel]

Yes - fingers crossed. It's lightened the wallet a little, but I've learned a lot. Hopefully this is it sorted. If you hear the faint sound of expletives drifting in on an east wind you'll know it's not over!

[Steve Le maitre]

Yes - fingers crossed. It's lightened the wallet a little, but I've learned a lot. Hopefully this is it sorted. If you hear the faint sound of expletives drifting in on an east wind you'll know it's not over!

You need to keep it away from that bloody salt water......

[Carlperkins]

All’s well that ends well

[andrew_nagel]

Yes - fingers crossed. It's lightened the wallet a little, but I've learned a lot. Hopefully this is it sorted. If you hear the faint sound of expletives drifting in on an east wind you'll know it's not over!

You need to keep it away from that bloody salt water......

There's no chippies over here, so I've taken it into my own hands. Life without fish-n-chips once in a while is not recommended. Good source of pike baits too, herring, garfish, mackerel...

[Alex Fox]

I change the thermostat on my outboard ( suzuki DF70 ) every year when i service it and its always about £50, bloody rip off, but its got to be done and must admit i did raise my eye brows when i read yours was a tenner !

Fingers crossed it was due to condensation, but in all honesty i doubt it, as i have read similar before and the outcome has been milky engine oil again and a bigger fix.

Hopefully it will be fine

[andrew_nagel]

The one for a tenner was an after market one that could be got just along the road to get the process of rinsing the engine underway. Now it's been replaced with a genuine Yamaha part that took a few days to get here. That was around £65. We'll see how it pans out, but it's running clear on the muffs now and the casings are warming up as they should so there's no excessive cooling going on any longer, which appears to have lead to the condensation. Time will tell.

[Alex Fox]

The one for a tenner was an after market one that could be got just along the road to get the process of rinsing the engine underway. Now it's been replaced with a genuine Yamaha part that took a few days to get here. That was around £65. We'll see how it pans out, but it's running clear on the muffs now and the casings are warming up as they should so there's no excessive cooling going on any longer, which appears to have lead to the condensation. Time will tell.

Hopefully it will be fine now Andrew

[andrew_nagel]

The one for a tenner was an after market one that could be got just along the road to get the process of rinsing the engine underway. Now it's been replaced with a genuine Yamaha part that took a few days to get here. That was around £65. We'll see how it pans out, but it's running clear on the muffs now and the casings are warming up as they should so there's no excessive cooling going on any longer, which appears to have lead to the condensation. Time will tell.

Hopefully it will be fine now Andrew

You've put the sh!ts up me now... I'll have to just hug the coastline next trip out and see how it does.

[Alex Fox]

The one for a tenner was an after market one that could be got just along the road to get the process of rinsing the engine underway. Now it's been replaced with a genuine Yamaha part that took a few days to get here. That was around £65. We'll see how it pans out, but it's running clear on the muffs now and the casings are warming up as they should so there's no excessive cooling going on any longer, which appears to have lead to the condensation. Time will tell.

Hopefully it will be fine now Andrew

You've put the sh!ts up me now... I'll have to just hug the coastline next trip out and see how it does.

Oh didn't mean to do that I would take it for a good run and go fishing as normal, then check the oil a few days later, if its cloudy, get it out quick so the water doesn't cause internal damage and go from there, would be good to know how it goes.

[andrew_nagel]

The one for a tenner was an after market one that could be got just along the road to get the process of rinsing the engine underway. Now it's been replaced with a genuine Yamaha part that took a few days to get here. That was around £65. We'll see how it pans out, but it's running clear on the muffs now and the casings are warming up as they should so there's no excessive cooling going on any longer, which appears to have lead to the condensation. Time will tell.

Hopefully it will be fine now Andrew

You've put the sh!ts up me now... I'll have to just hug the coastline next trip out and see how it does.

Oh didn't mean to do that I would take it for a good run and go fishing as normal, then check the oil a few days later, if its cloudy, get it out quick so the water doesn't cause internal damage and go from there, would be good to know how it goes.

Just playing Alex. That's the plan. Next trip out check the oil afterwards. At this time of year it usually 8 hours from motoring out to getting back into the harbour. I'll leave the engine running the whole time and see how it goes.