Please Help Fuel Useage and Gauge problems
Submitted by gib77 on Fri, 2011-05-06 20:07
I have a 1993 Grady White 24 with a 225 Yami 4stroke, and am having a few fuel issues. Mainly yamaha gauge doesnt seem calibrated/working consistently. I may be getting a air bubble in fuel tank when filling up also, meaning im finding it very difficult to sort out my consumption and amount of fuel left. Thinking of a fuel flow metre, or new sender. I run a lowrance HDS8, so wondering if there is a sender/flow metre that hooks up to it? Any help on subject would be greatly appreciated.
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Garbo
Posts: 86
Date Joined: 13/01/09
Change sender
I installed a new fuel guage in my boat and found i had issues with getting an acurate read, had a chat to my old man who is a mechanic and he checked the ohms on the sender to see if they matched my gauge and also to see if the sender was magnetic or not (think there is other types) anyway something along those lines i dont know alot about that sort of stuff so i left it up to my dad and he got me a new sender to match the gauge and he fixed the problem by doing that.
Tomcat
Posts: 614
Date Joined: 24/02/11
Fuel
You can get fuel meter inline for hds from lowrance cheaper on eBay
iana
Posts: 652
Date Joined: 21/09/09
Lack of fuel and battery problems.
Lack of fuel and battery problems, the two main reasons why boats need to be towed back to base. I put a new fuel guage and sender in my boat, calibrated it to the tank, then realised I had wasted my time. Yes it gives a reading but what the reading is depends on the attitude of the boat, nose up and it reads full, on the trailer different again, sitting stopped in the water different once more.
The only true reading you will get is at the bowser, fill up and note the amount, next trip, fill up straight away and note the amount.
This is absolutly true, I spent the first half of my working life servicing aircraft, and the fuel guage they used ---------- a piece of stick with notches marked in it. The pilot takes off the fuel cap and dips the tank, the only accurate way to do it. The guage being only a rough indication.
If you think that you have an "air bubble" in the tank, that could be a serious issue. The tank should be vented, and internally just off the vent (where it vents overboard) there should be a "Swan" neck bend in the vent pipe to stop water getting into the fuel tank. If the filler hose is not going into the top of the tank, i.e. enters, lower on the side of the tank, then that would be the reason why you are filling to different levels each time (The tank not venting to allow fuel to fill the rest of the tank).
If the vent is blocked, bent or crushed, and if the tank can't draw in air from else where, i.e. the filler cap, there is the possibility of the tank being sucked in. If the tank is venting else where you may also be drawing in water.
I know all the guys reguarly check the fuel vents, and it only takes an industrious wasp or something to block it off.
If you can easily reach the top of the tank, dissconecting the fuel vent and checking for blockages is the first thing I would do.
Auslobster
Posts: 1901
Date Joined: 03/05/08
Ian is spot on...
...I worked on three different crayboats during my time as a deckie and not one of them had a fuel gauge. Every once in a great while we used the "stick with notches" method! Once you understand your boat's consumption per hour/kilometre/nautical mile/etc, no gauge necessary!
In nearly sixteen years of driving my own small boat around, I've run out of fuel twice: both times I was well aware that I was close to empty before I started, both times I only went a short distance from the ramp, and both times I carried 10 litres of spare fuel in a jerry can so was able to get my own self back home.
By all means, sort out your gauge problems if that gives you peace of mind...because I have no fuel gauge I can't help you with that...but I would definitely agree with Ian's advice about filling up, going out, and then filling up again to see what your consumption is. In fact, do it over several trips because if you're like most fishermen you'll be asking your boat/motor to do different things that could vary fuel usage over time...drifting/trolling/cruising/5 and 8 knot speed limits/WOT...get yourself a good average over a bunch of trips and a lot of time!
roberta
Posts: 2773
Date Joined: 08/07/08
Iana so true
That is the most accurate way, as old fart has his notches on the gaff, he knows how much it wholes 100 litres, with 15 litres under outlet, (stops getting sh&^%t from the bottom of the tank,) left before he has to switch to the spare 25litre tank & other spare 25 litre for emergencies
"- a piece of stick with notches marked in it. The pilot takes off the fuel cap and dips the tank, the only accurate way to do it. The gauge being only a rough indication."
Ginger Tablets Rock
Hansie
Posts: 162
Date Joined: 27/03/07
easy fix
swap boats with your mate Hansie - he's got no problems with fuel guage or useage.
hmmmmm?
good luck Gibbo, sooner that is sorted - sooner we charge 'brolhos.
gib77
Posts: 53
Date Joined: 14/02/10
Cheers
Thanks for posts, I agree with idea of working out fuel usage. I am a big fan and had been doing this and had my useage at about 1.2 litres/km. I had some work done on my trailer to stop some swaying on the highway and this made the boat sit on trailer with nose down a little. Im thinking this could have an effect on filling the tank, although I do have a vent etc... My tank is meant to hold 350lt meaning I should be good for 290km(250km at least). Problem is I ran out after about 185km. Either boat started using nearly 2lt/km or boat wasnt full when I started. Either way not good. I think a fuel flow metre is the way forward, to know your optimum speed and useage. Anyone had any experience with adding a Navman or Lowrance
iana
Posts: 652
Date Joined: 21/09/09
Didn't think we gave the answer you wanted.
Didn't think we gave you the answer you wanted, however if you have a fuel tank running up the centre of your boat, so its quite long, (to hold 350 lts) and the vent and filling point are at the bow end. And you say the boat is sitting bow down on the trailer, doesn't take too much to work out what the problem is.
gib77
Posts: 53
Date Joined: 14/02/10
Yep tanks gotta be 1500mm
Yep tanks gotta be 1500mm long and yep filler and vent is at bow end so I was guessing im gonna have to take trailer off tow ball when fuelling to try and get it full. Or make more expensive adjustments to trailer. Bugger. I think ill still look at a fuel flow metre to try and work out where my best efficiency is though
iana
Posts: 652
Date Joined: 21/09/09
I think you've solved the problem.
The boat will have to be at least deck level or high at the bow when refueling. The flow meter I can't help there, I think I've read somewhere they are a bit tricky to set up. My brother inlaw fitted one to his commercial fishing boat, and they got better fuel economy it was diesel and a semi-dissplacement hull. If you are traveling distances on the same throttle setting there maybe an advantage having it fitted. Do you think that there is a problem with the fuel guage, or is the problem because of the air pocket in the fuel tank when refueling?