Fuel tank size ?

[PeterM]

After advice after I had a problem today that I think is down to running out of petrol, which in my mind is the biggest sin I can manage in a boat. I have been told by the previous owner & manufacturer that I have 180L tank , but after using 80L the low fuel warning popped up on the smartcraft gauge. I ignored it as I trusted the builder to know how big the tank was. I know the tank is roughly calibrated to be 180L.

Anyway , 200m out of the harbour, it dies on me. Started again & ran for 10 seconds, dies again. Got towed in , same again.

Now tied up alongside the fuel bulb is soft. Got towed back to the mooring, put 10 L in and I can feel the bud start pumping &the engine started & ran fine.

First question - am I right in thinking this si out of fuel ?

Second , any idea how to check the size of the tank ( its buried under the deck ! )

Thanks

[Jon.esp]

It's MT now so brim it and you will know how big the tank is.

Jon

[jyasaki]

After advice after I had a problem today that I think is down to running out of petrol, which in my mind is the biggest sin I can manage in a boat.

You obviously haven't tried too hard...

First question - am I right in thinking this si out of fuel ?

Sure sounds like it.

For a practical capacity, you had the optimum chance to see: You were completely empty; filling the tank would have given you a positive indication of how much fuel you can pull from the full tank before the engine dies from starvation.

Do you have a second tank in there somewhere that needs to be switched over?

jky

[Tim M]

To be doubley sure you could try siphoning any remaining fuel thats in there out then brimming it. I have been told my Solent has a 160l tank - we have put 200l in it

[Chris]

If your tank is supposed to be 180 litres and it runs out after 80 litres then there may be a problem with the pick up in the tank.

[PeterM]

Thanks for all the replys - it seesm like when I thought I had filled it up ( due to the pumps cutting out when filling it) , I hadn't . I worked this out as the smartcraft gauges told me I had used 95 L ( from full ), but I put 60 L in it manually on Saturday, then used 10 getting to Yarmouth , then got another 73 L in it at the pump . (Went to the folly had a nice lunch & came back etc etc )

All this means that the 95l I had used from full ( or what i though was full! ) was actually 95 l from near empty ! ( otherwise I wouldn't have been able to get 123L in over Sat & Sunday ! )

From this I have learnt I may have to slow down when filling, & may have to resort to a slow fill manually to what I know is an absolute full tank ! If anyone sees someone lugging lots of jerry cans around Dorset its probably me !

[Chris]

Originally Posted by Blackroady

Thanks for all the replys - it seesm like when I thought I had filled it up ( due to the pumps cutting out when filling it) , I hadn't . I worked this out as the smartcraft gauges told me I had used 95 L ( from full ), but I put 60 L in it manually on Saturday, then used 10 getting to Yarmouth , then got another 73 L in it at the pump . (Went to the folly had a nice lunch & came back etc etc )

All this means that the 95l I had used from full ( or what i though was full! ) was actually 95 l from near empty ! ( otherwise I wouldn't have been able to get 123L in over Sat & Sunday ! )

From this I have learnt I may have to slow down when filling, & may have to resort to a slow fill manually to what I know is an absolute full tank ! If anyone sees someone lugging lots of jerry cans around Dorset its probably me !

Don't you have a tank sender that tells you when the tank is actually full then?

[PeterM]

I do , but how can I say - its crap ! You can calibrate it , but it involves adding 1/4 tank at a time from empty - either i Have 180 L ( if thats what it is? ) in cans which would kill me, or I have to judge it so that I run out as I coast in to the pontoon ( also not a great idea). The other option is to allow the gauge to take an educated guess, but this wont allow for an odd shaped tank. I dont think its an odd shape, but who knows !

I had made sure the sender gauge 'knew' it was reading from a 180L tank , but even then it was saying low fuel at 80 L used (from what I thought was full so I ignored it- to my cost).

I'll be taking the sender out tomorrow & seeing if I can take an educated guess at the size of the tank by peering inside it , then I'll work on the assumption it was empty when the engine stopped , I know what I have used & put in so I know how much it 'should' take to fill it. I can only think it was not full when I thought it was, or the pickup is not at the correct height so there is still 80-90L in there it cant get to.

All will be worth it if I end up knowing what is going on - all this stuff is why I would always buy a new boat if I had the cash !

[m chappelow]

i only use the fuel gauge as a guide like everything else electric on boats they can give false readings try making a dip stick that way you know its right for a true second opinion , but it does seem that you may have a pick up pipe fault as someone else said earlier on , unless the boat was not level when filling ,up or the gauge sender unit is set up wrong.

[captnjack]

Slow down when filling - will let air out easier and the fuel won't "surge" back up the fill nozzle and trick you into thinking its full.

[Hightower]

You've lots of good advice and I would suggest you do the following, this will tell you lots of things I think everyone should know about their fuel systems.

Starting from scratch:

First disconnect the fuel line and using the primer bulb try and suck out fuel into a container (I guess the 10 litres you put in afterwards would be enough). If plenty of fuel comes out then I guess there might be another reson for your motor cutting out. If none comes out go to the next step.

Physicly measure the amount of fuel in the tank. Take out the sender unit and insert a piece of rod to get a measure on how high the fuel level is referance the bottom of the tank. This will then tell you if the fuel pickup is on the bottom of the tank or not. If the level is high then it might be possible that the pickup tube isn't on the bottom or something is obscuring the tube preventing flow.

If the level is low, you're empty.

You could also remove the pickup tube at this point and see what you've got.

I would suggest that you empty the tank completely and note the amount of fuel that it takes to fill in one go. This will give you a good idea if you can get the full capacity or not. Bear in mind that the boat level on the trailer might be different from that in the water.

If the pump keeps cutting out then either reposition it in the fuel filler neck or get a bigger tank breather. The pump often cuts out when I start to fill mine up. This is because there is a bend in the tube that causes the fuel to back up a little. If I pull the nozzel out a little it fills without problem.

Hope this helps,

[Hightower]

Originally Posted by Blackroady

Saturday, then used 10 getting to Yarmouth , then got another 73 L in it at the pump . (Went to the folly had a nice lunch & came back etc etc )

The Searider Cruise boys where at the Folly on Saturday, did you not see all the RIBs just North of the Folly Pontoon?

[PeterM]

Sorry - not clear - went up from Chirstchurch to the folly on Sunday - the only real summer day I have had this year ! Couple of boats but none that I recognised to say hi .

[Hightower]

That's a shame. Next time perhaps

Just follow my instructions, it's a little longwinded but will tell you everything you need to know.

[PeterM]

Will do & I don understand what you mean to do . I've just toped it up as far as possible and managed to get 120l in - so either it is a smal tank , or the pick up is missing around 60l worth. I know all tanks have an unusable amount & have always been paranoid about it as its somehting I learnt when flying - never trust the gauge. But was stunned it ran out after using 95 ( according to the fuel used gauge, which seesm pretty accruate compared with the LPH and what I have been doing. )

So tomorrow night the sender comes out and I 'go in' - I have already stunk the house & car out with petrol so it cant get any worse !

Thanks again for all the info - As an aside I managed to upload a few videos to youtube :

http://www.youtube.com/watch?v=WmlCS-e52V8

etc

[Chris]

BlackRoady,

Why don't you run you tank down as far as you dare then go to the pontoon and moor up. Then use the primer bulb to draw out any remaining fuel into a jerry can. Once you have done this re run the calibration process on your smartcraft guages

[Hightower]

Originally Posted by Blackroady

Thanks again for all the info - As an aside I managed to upload a few videos to youtube :

etc

I liked the Videos, perhaps if you have the time you could post some pictures in the Gallery of the rest of the RIB, I'm interested in seeing the cabin and cockpit area.

[Downhilldai]

Originally Posted by Blackroady

So tomorrow night the sender comes out and I 'go in'

You may find it easier to 'go in' via the filler tube fitting, rather than the sender.

As an aside, I find the Smartcraft fuel flow and level gauges to be very accurate, so I'd be surprised if this is your problem.

[Searider]

My Smartcraft "fuel used" trip always says i've used a little less than I manage to get in the tank when I fill up - perhaps a 5% difference.