How bad is running out of fuel?

[WalrusLike]

:)

I know it's pretty bad if it happens by accident, but I am thinking of doing it deliberately a couple of times.

The newly installed fuel flow sensor seems pretty accurate but now I need to know how much total fuel is available in the tank. It depends on the pickup height and a bunch of other factors no doubt.

My fear is that running it out of fuel
a) might be bad for the motor
B) it might pick up dirt from tank bottom
C) it might be hard to reprime.

It's a 2011 Yammie 115 2stroke Saltwater series.

I realize that you always factor a safety margin of fuel in your trip and that I could just estimate it, but I would like to know more accurately.

Any thoughts fellas?

[lucee81]

Most people pull the line out of their engine and run it empty when flushing. Also your filter/s should stop any crap getting in. My fuel flow sensors epr66 doesn't work. Could be user but lets not go down that road. Will do a full reset and try again.

[Dicktracey]

:)

I know it's pretty bad if it happens by accident, but I am thinking of doing it deliberately a couple of times.

The newly installed fuel flow sensor seems pretty accurate but now I need to know how much total fuel is available in the tank. It depends on the pickup height and a bunch of other factors no doubt.

My fear is that running it out of fuel
a) might be bad for the motor
B) it might pick up dirt from tank bottom
C) it might be hard to reprime.

It's a 2011 Yammie 115 2stroke Saltwater series.

I realize that you always factor a safety margin of fuel in your trip and that I could just estimate it, but I would like to know more accurately.

Any thoughts fellas?
Why chance getting caught out mate ?
Run the tank down low with a small local trip have a Jerry on board just in case, then when home disconect fuel line down stream of primer bulb connect to a length of hose and run out through hole in bottom of transom.That will let you drain tank into containers and see whats in bottom of tank.
Then go to servo and do a calibration check on your gauge and check every 20l you put in get someone in boat to switch key on and check fuel gauge even mark with small nikko pen line.
The only time you have too much fuel mate is when your on Fire ;)
Dick

[lethal098]

If you are underway with mid-high RPm it can definately damage your motor, It can cause the motor to lean out becuase it does not have enough fuel.

Take the hose off and drain the tank at home as said above.

[Noelm]

any dirt/water/crap is always at the bottom of the tank, regardless of how much fuel is in the tank, now i know there is less fuel for the rubbish to "float" around in, but as a general rule, it is always right on the bottom (where the pickup is) running out of fuel with your "old" 2 stroke is not going to hurt it, and re-priming is also not going to be a big deal, but it may take a few minutes of pumping the primer bulb.

[uripper]

I just bought a second-hand boat took the following precautions:


major diagnostic service of engine



replaced crappy fuel filter with quality item that has a clear section at the bottom so I can easily see if there is any water et cetera



drained all fuel from tank - if you're not confident with that then suggest remove it and manually rinse /drain to remove all (if any) impurities


Also suggest


always carry some spare fuel in a separate container stored underfloor or transom area (not in cabin)



do not use any fuel older than four months - drain / siphon and put it in the family station wagon mixed with new fuel no more than 50-50 (if you are game)



re-priming should not be an issue



fuel flows sensors can be erratic particularly at slow revs /speeds and should be cross checked against other measuring methods


Mal

[Mossy247]

Most people pull the line out of their engine and run it empty when flushing. Also your filter/s should stop any crap getting in. My fuel flow sensors epr66 doesn't work. Could be user but lets not go down that road. Will do a full reset and try again.
Most people usually fill their tank hey Lucas :-p "Oh crap Mossy might have to walk back to pinkenba" LoL Good times.

[lucee81]

Most people usually fill their tank hey Lucas :-p "Oh crap Mossy might have to walk back to pinkenba" LoL Good times.
Most people arent like me.

[lucee81]

And you didn't have to swim so stop whinging.

[Moonlighter]

I know what you are intending Walrus, you want to really know what the "useable capacity" of your tank is, right? Not the actual capacity that it will hold, but the amount you can get out of it from full!

So to answer your questions:

No, running out of fuel on your Yammy 115 2 stroke won't hurt it. You will be zooming along and will feel it lose power, simply back off immediately and chuck it into neutral and then turn it off.

We used to do that all the time in a mates boat with exactly the same motor as yours, he had 2 underfloor tanks, it would run out on one tank, and if we were quick, we could even quickly turn the fuel tank switch to tank #2 and keep the motor running! But if we weren't quick enough, it would stall, and all we would have to do then was pump the bulb up again and start her up and away we go. No, it won't be hard to reprime. Worst case - take a small can of fuel with you and a filter remover so you can remove the fuel filter, fill it and go from there. But I doubt very much if you will need to do that.

Once it runs out, then you can refill with petrol from the gerrys that you will have ready filled with an exact known quantity of fuel, or, better still, you will disconnect the main tank from the motor and run home on an auxilliary 20 litre tank. Then when you go fill up the main tank, you will know exactly what your useable capacity is, right!

I don't know how accessible your fuel tank cap is, but really, the safest way to refuel at sea is to use a pump or jiggle syphon, I use the syphon, yes, it is a bit slow and a 2 person job, but it is much safer in most cases than trying to pour gas from a 20 litre jerry into a boat tank while things are bouncing around in the ocean.

You should only need to do this procedure once. That will give you close enough info for the purpose you have stated.

Yes, there is the issue that running the tank to empty you can get the crap from the bottom. But you have got good fuel filters, so that's ok.

Plus, if there really is that much crap in your tanks that it clogs the pickup, better that it does it on the "test" day when you do this procedure and you find out then, so you can then get it cleaned out properly, hey!

Cheers

ML

[WalrusLike]

Thanks fellas for the good advice. I appreciate it especially since its given me the way forward. I hadn't thought of some of those tips.... thanks.

I think I will run it down then empty the last of the tank with the primer bulb.