Mercury Optimax Gauges... reliable ?

Scotty · 19 March 2005, 20:05

I bought "mikes" valiant dr 600 and am very happy with it. It has smart gauges fitted to the console and I'm curious as to the reliability of the fuel gauge. Mike had filled the boat with fuel before he delivered it to me, and every time I take it out it shows 56 gallons. Is the optimax very miserly on petrol or have I an issue here with the gauge or sender in the tank ? I'm getting worried.

Turbodiesel · 19 March 2005, 20:25

It depends, the Optimax gauges will only read from a Wemer ( i think thats how you spell it!!) Fuel tank sender. Otherwise you need to run a seperate fuel gauge. Also you need to check a few things. If you have a Wemer sender then you need to make sure the gauge has been calibrated correctly. When In CAL 2 on your gauge you need to tell the gauge when the tank is empty, Half fuel and Full. Its a pain in the arse to set up!!. Check in your owners manual to see how to get to the gauges Calibration. Also you must check that the gauge is set to display the fuel tank level, this is also in CAL 2 you can either switch the tank display on or off. If its switched on and is not able to talk to the fuel tank sender it will display it as a fault because the wont be able to get any info from the sender. Sounds complicated but its quite easy really!!!

Dirk Diggler · 19 March 2005, 20:32

Quote:

Originally Posted by Turbodiesel

the Optimax gauges will only read from a Wemer Fuel tank sender.

I don't think that's quite true, I've seen all different makes of senders being used!

Turbodiesel · 19 March 2005, 20:40

Quote:

Originally Posted by Dirk Diggler

I don't think that's quite true, I've seen all different makes of senders being used!

Well maybe, but im just going on what i was told at work the other day when i fitted a 135 opti to a Delta Rib. Will find out when i get into work on Monday for sure.

Scotty · 19 March 2005, 21:16

Oh feck ! Now here's another reason the zodiac was so good... You could see the level of fuel in the tank. The tank in the valiant is under the floor. Mike.. Mike are you out there ? Was the fuel gauge accurate ??

Paul F · 20 March 2005, 08:11

Cant say about being accurate, but can say that it was working and was callibrated by me using the take it to a petrol station and slowly fill up method.Sender is correct and wired correct. Have you accidently gone into callibration mode and inputed the wrong info?
Paul

Scotty · 20 March 2005, 13:35

Quote:

Originally Posted by Paul F

Cant say about being accurate, but can say that it was working and was callibrated by me using the take it to a petrol station and slowly fill up method.Sender is correct and wired correct. Have you accidently gone into callibration mode and inputed the wrong info?
Paul

Paul,
Thankfully I never touched anything. It just seems to be very economical. Mike had left a lot of fuel in the boat and the gauge says 56 gallons still. Maybe I need to go for a very long journey to check economy /gauge. I was going to open the fuel gauge inspection cover but brought the wrong screw drivers with me.... maybe just as well. Paul F my mobile no is +353-86-2552012 if you text me I will call you back to discuss this. Thanks for all your help.

Luke.

Cookee · 21 March 2005, 11:02

Wema US spec senders were recomended by Barrus to me - There is no reason why other makes shouldn't work if they have they same resistance and wiring.

Daniel · 21 March 2005, 12:28

As a rule of thumb that engine on that boat will burn about 30li's an hour and a litre a mile upto 3/4 throttle / speed, almost regardless of any other factors.

Why are you using the "float" gauge - it'll never be very accurate on any boat with any tank. The opti "fuel used" gauge is very very accurate - if it was reset when the tank was full you can have good confidence in the amount left.

Scotty · 21 March 2005, 13:12

Quote:

Originally Posted by Daniel

As a rule of thumb that engine on that boat will burn about 30li's an hour and a litre a mile upto 3/4 throttle / speed, almost regardless of any other factors.

Why are you using the "float" gauge - it'll never be very accurate on any boat with any tank. The opti "fuel used" gauge is very very accurate - if it was reset when the tank was full you can have good confidence in the amount left.

I think its time to fill the tank and read the manual

mike · 21 March 2005, 14:36

Hi scotty, glad to see you using it. The boat had 240 ish litres when I delivered it to you, the likyhood is that it may need to be recalibrated as it always worked depressingly well. Just before we sold it the trim metre was renewed as it had never been operational and I wanted it all shiny for sale.

Theres a chance that somewhere along the line it was reset as when I used it it was set to litres.

The best way is to refil and recalibrate at the same time to full then test it by running, if theres no drop in ltres there must be a fault in the sender which is located in the small awkward black deck hatch under your left foot.
definately get your mate to have a look as it was something I never needed to do so can't suggest a way to do it!

have you taken any pics yet??

Daniel · 21 March 2005, 14:47

Sounds like a full reset occured when new trim sender was installed and it's also reset the float gauge calibration. I've had reasonable sucess using "default" calibration settings (i did exactly the same when a new trim sender was installed!!!)

Scotty · 21 March 2005, 17:21

Hi Mike,
Thinking about it I think we have only used the engine for 6 hours tops since you sold it to me. So maybe the gauge is not too far off. No pics yet. I will take some this weekend and email them to you. Is recalibrating a big job ? And do I have the instructions in the "brown box" ?

The boat is a flyer.

Regards,

Luke.

mike · 21 March 2005, 19:45

Yep the box has the stuff, but the default is the way to go I feel, fill it up and slap 240 litres in as the quantity.
if you want more safety marigin tel the unit that its full with 220 that will give you 30 in reserve all the time.
paul Fenn is the chap to ask as I am so rubbish I had to tow him and the boat to the petrol station when we remortgaged to fill the new one up!!!

Turbodiesel · 22 March 2005, 20:17

Its ok im talking rubbish. We recomend Wema ones at Barrus because they are apparently the easiest to get hold of in the uk. You can use any american Spec fuel sender (what ever that means!!)

ashbypower · 22 March 2005, 20:27

Whilst on the subject of smartguages, can anyone help me in sourcing a manual for the square type? it's running version 1.02 software. Looked everywhere on the net and failed miserably.

Thanx in anticipation.

Brian

Dirk Diggler · 23 March 2005, 08:54

Quote:

Originally Posted by Turbodiesel

You can use any american Spec fuel sender (what ever that means!!)

it means a sender thats gives a value of 240 ohms empty, approx 103 ohms at half tank and 33 ohms full, these type are most commonly used with USA made instruments, Euro senders are needed for VDO instruments.

You'll quite often find US spec instruments read backwards on some Volvo motors, easiest fix is to replace sender.