Old oil tank sensors

[Sancha]

Just a best practice for anyone in need. I run two old (1986) Yamahas on my Sailfish 25. The oil sensors on the main tanks work loose and rise out of the tanks. Ace hardware has SS tie wraps that fit under the collar on the tank. Tighten till the sensors can't raise with vibration, stopping the remote tank from thinking the main tank is low and overflowing the main tank. That stopped that issue. Hope this helps.

 

[Byram]

Thanks for the headsup

 

[seasick]

Just a best practice for anyone in need. I run two old (1986) Yamahas on my Sailfish 25. The oil sensors on the main tanks work loose and rise out of the tanks. Ace hardware has SS tie wraps that fit under the collar on the tank. Tighten till the sensors can't raise with vibration, stopping the remote tank from thinking the main tank is low and overflowing the main tank. That stopped that issue. Hope this helps.

Good tip about the ss tie wrap.
One minor detail on the explanation. The remote tank doesn't know what the level in the main tank is. . The main tank detects a low level and sends power to the remote pump.
In your case, when the main sensor assembly popped up, the high level reed switch couldn't be activated and the tank overflowed.

 

[ROBERTH]

The only issue I am having is that in the remote tanks, I have leaking oil around the small orifice, not the fill. I am not yet sure if there is an Oring in there that needs replacing or if the entire rubber grommet has shrunk. It is doing this on both remote tanks. Hope to pull floor hatch before spring and check it out once my broken ankle heals...

Anyone have any experience with these Yamaha remote tanks leaking and how to fix?

 

[seasick]

What small orifice are you referring to?

The tank is for the most part sealed. The more common oil leak is out the sender cap which gets loose over time. However if it is leaky it does not leak during normal operations and when the motor id tilted down. It leaks when the motor is tilted up. Often that oil will leak into and pool in the lower cowling. Often you don't see that oil leaking until the engine is lowered and the oil runs down the exhaust housing. If the main oil sensor is not working correctly the tank can over fill and leak. That is kind of easy to check. If you run for a while at idle or even just with the ignition on and then turn the motor off, pull off the cowling and check the oil level in the tank. It should not be full to the top.

 

[ROBERTH]

Hi Seasick, the oil tank I am talking about is the 2.5 gallon installed under the floor panel.

 

[seasick]

I am nor sure I have seen that fitting leak and to be honest, I don't see how it would unles the tank were filled to the brim with oil. I suppose oil can slosh around and maybe seep a bit. How bad was the leak?

Can you tell me why the oil stain in that tank seems vertical and not horizontal? It looks like the tank was kept on it's side but that makes no sense

 

[ROBERTH]

That is a random picture, not mine. Just showing you the neck that is supposed to be sealed with the fitting. I need to get down in there and check it further. I had planned on pulling them out this down season to clean up and recoat the brackets as I see they are rusting a bit and then I could get a better idea how or why they are leaking out.

I always fill the tanks before going offshore and yes, I am sure it is due to sloshing. But, they should not be leaking. They should be sealed. They only started doing this in last couple years.

 

[DennisG01]

I'd be willing to bet what is happening is that the rubber cap is simply old and hard and not sealing as tight as it should. You might be able to seal it up with something like Merc's "Perfect Seal" or similar. It's a non-hardening gasket sealer that isn't affected by gas/oil, etc. - pretty neat stuff, actually. I use it on my mooring shackles to make the pin easier to remove in the Fall... 6-7 months in the salt and it DOES NOT wash away!

FYI... if you need to replace the hold-down bracket.... be sure you're sitting down when you see how much they are! Although, they do have Mother Yamaha's approval... BUT... guess what works PERFECTLY well for about $10? A regular 'ol battery tray with a strap!

 

[ROBERTH]

Haha, Dennis, yeah, they are proud of their bracket system. For sure, a battery tray system would work out as well. I made my own out of some SS threaded rod and Starboard or PVC for my house batteries, sitting on a foam exercise mat for shock absorption and has been the best battery tray. Not restricted by size of battery. I might have to do the same for those painted brackets.

And agree, likely has hardened over time, even though it is oiled up all the time.....I will check out that stuff for sure!

 

[seasick]

That is a random picture, not mine. Just showing you the neck that is supposed to be sealed with the fitting. I need to get down in there and check it further. I had planned on pulling them out this down season to clean up and recoat the brackets as I see they are rusting a bit and then I could get a better idea how or why they are leaking out.

I always fill the tanks before going offshore and yes, I am sure it is due to sloshing. But, they should not be leaking. They should be sealed. They only started doing this in last couple years.

Ha, the old bait and switch!

Do you fill using the screw cap or are there hose extensions from the tanks to a deck fill fixture?
The caps do get stiff and loose over time but often can be 'fixed' by cleaning the lip and cap and adding a wire tie around the outer lip. While you are at it, make sure that if the tank opening has a tip or key, that it lines up with a space in the the sensor cap. I think there is such an arrangement on the main oil tank sensor cap

 

[ROBERTH]

Fills are on the transom with hose going down to tanks. No leaks there or around the fitting where it connects the hoses to the tanks. The leak is where I said due to that fitting not sealing anymore. I did reach down and could move them without much effort, so to me, they have either shrunk or the plastic tank has expanded, or there is an Oring that needs replacing.
Guess I will not know until I pull her apart to check it.
I am very anal about checking and making sure no leaks anywhere and seals are perfect shape. My bilge is spotless until this leak started so I have some oil residue I have to clean up periodically.

 

[ROBERTH]

I think I finally found a pic on this part. It is actually the float for the pump. Here is a pic and it totally looks like it might have 2 orings that might be the culprit.

 

[seasick]

It is the sensor. I also understand why you tank leaks. Since you have fills on the gunnels, it is easy to actually fill the tank all the way to it's top. On one of my boats, it is just about impossible to see the oil level in the tank and it is kind of normal to fill till the filler overflows or at least fills up to it's top which is higher than the tank top.
In your picture I see that gap I was referring to. There is a tab on the tank sender extrusion and if they are not lined up, leaks are more likely at least for the main tank sensor. I also see those O-rings and that may very well be the whole issue.