Tank monitor Calibration

[spiderbill]

I have a 2011 42DS and have just returned from my first trip aboard. My water and fuel readings are erratic. The water tanks read 1/2 full but are apparently empty since the pump will no pick up. When I switch to another tank the pump works so it must be a incorrect reading.
What bothers me the most is my fuel read-out. I am on my first full tank of fuel and have run about 8 hours on that tank. The meter still shows the tank as full (Yanmar 4JH5E engine). Now I don't trust the meter.
Has anyone calibrated their tank monitor system and if so, where can I find the instructions?
Thanks for your help.

[rc sail]

Congrats on your new 42 DS. I have 07 39 DS and the aft water tank stopped reading after one year. I would suggest filling your tanks with various amounts and check readings. When I switch tanks it sometimes takes the water pump a couple of minutes to reprime and put out water.
After fuel fill I can motor for some 5-7 hours before the fuel reading will drop to 3/4 (4JH3E engine) so perhaps give the fuel reading a couple more hours of engine time. I do keep a fuel log and for my engine at cruise I burn .5-.7 gal. per hour.

[spiderbill]

Thanks for the reply RC. I will be a little more patient with the fuel reading and see what happens after 3 or 4 more hours running. In the meantime I'm going to buy a fuel can to have on board just in case.
I contacted my dealer and he replied that they haven't had any trouble with the tank monitors. He said they arrive empty (no kidding) and they fill for the first time and get full readings so no calibration needed.

[sitara]

I noticed when filling the fuel tank for the first time on our 2012 SO36i that the readings appeared pretty accurate. I was adding 30 L at a time and each time the level increased by 1/4 which is about right on a 130 L tank. Water levels are another story. The rear tank reads 3/4 when full and the front tank seems to fill the bottom half of the tank very quickly. I plan to calibrate these gauges - which seem only to give 0, 1/4, 1/2, 3/4 and full readings - by adding water in 20 L increments from empty.
A job for next season!

[spiderbill]

Good idea Sitara. Jeanneau America informed me that there is no calibration procedure for the panel itself but I like your idea of a measured fill-up when tanks are empty. My boat was delivered with a full fuel tank which was causing the tank to bulge around the area near the tank sensor. I suspect that the fuel has not dropped enough to show the 3/4 mark. Maybe even some fuel was in the fill pipe. Puzzles me how it would not have backed up through the vent if it was that full.

[sitara]

Spiderbill,
I did not make it clear - the fuel sensor in my 36i is different from the water sensors and gives an almost continuous reading - not like the water sensors. If your fuel tank was full, with a bit of a bulge and with some fuel up the filler pipe, it may take a while for you to use enough to show on the gauge. I have a couple of hours on the clock since filling the tank to the top and the gauge has not dropped from full yet. This will also be a function of wide shallow tank.

[shiook]

My fuel gauge was replaced last summer after the new boat was delivered. It was not working. The display read nothing.

Actually both the gauge and the main display board were replaced at that time but the board was replaced to correct an LED and circuit issue with the deck light.

[spiderbill]

Shiook...I hope that's not the case with my boat but I have read that the "fix" for a bad tank monitor is to replace the whole panel.
Good luck and let me know if that takes care of the problem or if you discover something else.

[johnnyboy]

spiderbill; i have a 2010 42 ds. same engine. i'd think the tanks are the same. what i learned with the fuel meter is that it is not accurate due to its shape of the tank

when filling the tank, when your fuel meter reads full, you can add another 10 or 11 gallons of fuel. we learned the hard way.

its a 34 gallon tank. i kept track of fills and tank readings last season. i have them at the boat and will post for you next week. i do remember that when the tank reads half full, you only have about 7 or 8 gallons left.

i don't think i had too much problem with the water tanks. when one was empty, it read empty.

[johnnyboy]

spiderbill, are you a member of the Jeannea Sailboat Owners group? (JSO)? i see you are from the middle chesapeake. there is a new chapter in the middle/upper bay area. there are some raft ups planned very soon. check out the website to sign up. iit should be fun. good opportunity to compare notes on similar boats with nice people.

www.jsogroup.org/

[johnnyboy]

here are a couple more readings:

at 7/8 full, there is about 18 gallons left
at 3/4 full, there is about 14 gallons left
at 3/8 full, there is about 6 gallons left

these are based on one seasons use and record keeping.

[spiderbill]

Johnnyboy,
Thanks for all of the fuel tank info. Probably explains the bulging tank upon delivery from the dealer. Do you have any numbers on gallons per hour?
I am not a member of a Jeanneau Group but would like to join up. I'll check it out.
Spiderbill

[j]

If it helps - this is what the fuel level sender looks like in an 2009 36i with 126 litre tank.

www.vdo.com/generator/www/com/en/vdo/main/products_solutions/special_oem_solutions/platform_products/sensors/fuel_sensors/hidden/adjustable_lever_type_sender/adjustable_fuel_lever_arm_sender_en.html

www.whitworths.com.au/main_itemdetail.asp?cat=114&item=34122&intAbsolutePage=1

At 1/8th on the gauge there is about 10-15 litres left in the tank.

Also, the tank sort of has a sump and there is a bolt on the corner closest to the engine (which I assume is for draining, but I haven't used it)

[johnnyboy]

average fuel consumption for the season was .9 gallons per hour. i followed the yanmar break in pretty close, so i think a good bit more fuel was consumed because of that. i think the yanmar book recommends a cruising rpm of 2800 which is a pretty good clip. i may back that down this season to around 2600 and should see better fuel consumption.

[spiderbill]

Thanks "J".

Johnnyboy...2800 rpm seems a little high.I was told that the max rpm was in the 2300 range.

I have now put 23 hours on since my first fill up and the fuel meter still reads 7/8 full.

My #2 water tank is empty when it reads 1/2 full and my #1 tank is empty when it reads 1/4 full..

I'm not happy!!!

[johnnyboy]

spiderbill; at 7/8 full, i figure you have used 16 gallons of the 34 total assuming you filled it until could tell that the filler pipe was full. if you are cruising at 2300 rpm, you should be getting .75 gal per our. 16 gallons at .75 is 21 hours. pretty close to what you got.

its pretty safe to assume that the fuel gauge is not accurate.