Water in fuel

[garfield28]

Hi all, 

I believe I have water in my fuel and the other day while on the water it caused the outboard to conk out and I couldn't get her firing again. 

Just wondering if my outboard will be stuffed now, and it is there anything I can do to kick her over again? 

 

Thanks 

Geoff 

[kingfishbig]

If it is a carby model then it's probably just a matter of drying the carbs with compressed air (might be best to get a mechanic to do it). If it has fuel injectors sometimes they can be dried/ cleaned up if you get onto to it quickly or at worst you will be up for new ones.

And of course it is important to work out how the fuel got contaminated and rectify it.

[JonD]

Using a filter with the clear bowl so you can check for water ahead of each trip is also advisable. 

As for how it got there could be down to all kinds of reasons, firstly from a seller with water in their tanks. Keeping your fuel tank filled helps prevent condensation mostly caused from temperature variations. E10 fuel is known known to cause water in fuel, something to do with the ethanol ( simply don't use it ).

If it's a built in tank make sure it's not saltwater entering through a breather outlet. A mate ( abalone diver ) recently managed to get water into both engines from backing up in rough seas taking water through his breather outlet.

As sated above older carby outboards are often a much quicker easy fix. High pressure injection systems can be quite costly which is why most of these type engines have filters under the cowling and alarms to warn of any moisture. If it's a high pressure system you are unfortunately at the hands of the mechanic so make sure you use a good one with a good reputation. I also recommend getting the fix done sooner than later, you don't want water sitting in the system.

[rickmarlin62]

what motor do u have

[garfield28]

I have a Merc Saltwater series 125 Rick.

 

I had water in the tank last time I had it serviced and the mechanic told me to pour a lt of Metho in the tank. I only use straight unleaded I never put E10 in my boat.

Also, a mate told me about the water separator which I have but didn't know I had to drain it, but after I spoke with him I jumped up and had a look sure enough it was full of water which I have now drained. 

[zmk1962]

I would not put metho anywhere near your 125 fuel supply.  It was not designed to run alcohol fuel mix and you will be just propagating more water through your engine. 

I’ll post more later just on my way to a meeting. 

Cheers Zoran

[zmk1962]

Back now...   @garfield28 I wrote about metho and boat fuels a few years back... generally the metho approach may be ok for removing water in tanks in cars where the fuel tanks are smaller and used up quickly, but not ok for boats - especially older 2-strokes.  Boat tanks are bigger and don't get fully drained often - so fuel sits idle for long periods and the alcohol will separate out into water and acetic acid (vinegar). Also, older 2-strokes were not designed for alcohol mix fuels and 2-strokes by nature use the fuel+oil mix as a lubricant - so you may have water sitting on your internal crank bearings etc. So the sooner you can get it running with clean fuel+ oil the better. New two strokes use s/steel components so claim to be ok with E10 type fuels.

If you have water in the tank, its best to drain the tank and fill up fresh. 

 

Back to your question, your motor may NOT be stuffed but you should be looking for a way to attach clean fuel+oil as soon as possible and crank her over  - perhaps borrow a portable fuel tank and attach that.

BTW, I also run a Merc Saltwater 200 EFI so have some personal experience with that engine design.  Is your 125 an EFI or carbie model?  Do you premix, or does your 125 have an oil reservoir and mixes as it goes?

Regarding the Engine:

I am not sure how much water you got into the engine - remove the plugs (check if they are wet) and crank her a few times to make sure there is no water in the cylinder heads.  You can spray a squirt of WD40 in the cyl chambers - wont hurt ( may be a bit smokey next start though). Also be aware that WD40 is combustible - so at the next crank with spark plugs back in she may fire up.  Water in the cyl chamber will stall an engine but given water is incompressible it can do a lot of other damage - bend shafts, destroy piston heads etc.  Cranking with the plugs removed will give you an good idea if everything is still intact.

Regarding the fuel supply:

If its an EFI, and water has got into your EFI it may have caused damage to the seals, water behaves differently to fuel in the high pressure EFI pump.  You should drain the EFI pump ASAP, and also replace the final Fuel filter mounted on the engine block - this would have to be full for water to enter your cyl chambers - so it needs replacement.  BTW an alarm should have gone off as that final fuel filter has a water sensor.  After all that, connect clean fuel+oil prime the system and crank her over.

If its a carbie model, its a bit simpler. There should be a screw to drain the carbies. Undo that to get the water out. Prime the carbies and crank her over. 

If she starts - let her run for a while to warm up and expel all the water.

Hope this helps.

Cheers

Zoran

PS - I have sent you a PM as well.

 

 

[kingfishbig]

I don't think water is likely to get past the carbies - if this was common then motors would be dying from water ingestion on  a regular basis. But the carbies might need a bit more than draining if they have had a good does of water, ie drying with compressed air.

[garfield28]

Thanks for all the replies. I have the boat at the mechanics and just waiting to hear from him what it is. 

Will post on here once I have heard back from him. 

[zmk1962]

All the best @garfield28 hope the mech is kind ! 

 

On 9/12/2018 at 8:16 AM, kingfishbig said:

I don't think water is likely to get past the carbies - if this was common then motors would be dying from water ingestion on  a regular basis. But the carbies might need a bit more than draining if they have had a good does of water, ie drying with compressed air.

@kingfishbig all I know from experience is that water did get through my EFI pump, past the injectors into the engine, and it did cause the big end bearings to pit. After we replaced the EFI pump and the engine kicked over it sounded like there were loose bolts clanging around - not pretty.   In my case, there was a significant layup time (6mths) between motor starts as I was living in Singapore at the time and only started the motor on my periodic returns to Aus.  

The EFI Merc has a final filter on the engine block which has a water sensor - and this did not sound the alarm. There was a small residue of water in there, but not at the level to sound the alarm (the mech and I checked)

So our conclusion was I had got a bad batch of fuel or was sold an E10 type fuel.  The fuel and alcohol (ethanol) had separated in the EFI pump chamber over the 6mth layup. The last start up attempt had injected some water into power head. And since the fuel is a lubricant in 2St motors this was left in the engine block. 6mths later the big-end bearings had pitted .

We pulled the EFI pump apart as well ---  as it was seized and there was a rust line in the chamber where the separation had occurred. which validated our earlier conclusion.

Sadly this was a painful and expensive experience for me and not a theoretical discussion about how likely water was to get past injectors/carbies. It does and can.

As I shared with @garfield28  my take away from this experience is to get the motor started ASAP with clean fuel of correct oil mix  and things should be ok. Time is the enemy with the engine sitting idle. 

Cheers

Z

 

[kingfishbig]

Yes but I was talking about carby models - not fuel injected motors. The former seem a lot more tolerant of  water in fuel than the injected motors. Eg I have had water in fuel many times with several carby outboards with no major problems. Ie they ran fine once the fuel system was cleared of water. In any case there is not much more you can do except get it running quickly, as you said.

Edited September 20, 2018 by kingfishbig

[zmk1962]

Yes EFI injection systems are more prone to water damage than carbie. But regarding internal water damage- carbie models are less fuel efficient than EFI. So logically they suck more fuel and if there is water in the fuel more water. The lubrication cycle is the same in EFI or carbie models. The key parameter to prevent internal damage is time. How long did the motor sit before being started with clean fuel. 

Z

[kingfishbig]

Not immediately but a week or so as I got the mechanic to do it. Actually I have had water get into the internals via a head gasket leaking. In this case the piston rings seized in the cylinder after only a week - ie it was enough time for corrosion to start.  But like I said nothing like that has happened when water has been in the fuel. 

[garfield28]

G'day all,

Thanks for the replies to this thread. 

I have got the boat back, it had water in the fuel and also a burnt wiring harness somehow. The mechanic said it sometimes happens in mercs when a new battery is installed, I told him I never changed the battery but I did replace the dual battery switch and from the moment I did it was playing up a bit when on battery one... now I know why. 

Thanks again,

Geoff 

[zmk1962]

Awesome news Geoff. Glad you are up and running. And THANK YOU for coming back with an update to close out the post. 

Cheers

Zoran