190 MONTAUK Fuel Tank Level Gauge; Fuel Management

[Tacky79]

Had a nice evening on the water yesterday around dusk, skiing and snacking with the family.

I don't have confidence in the fuel tank level as shown on the gauge on the 190 Montauk. The 190 Montauk should carry 60 gallons of fuel when full. It seems that a 1/2-FULL tank lasts forever, then it rapidly goes towards empty.

I put in 10-gallons on the way to the lake; that put [ the tank level gauge to] about 1/4-FULL.

I'm having a hard time deciding how to trust my fuel gauge.

I know that carrying more fuel is safer, but it seems a bit ridiculous to carry a FULL or 3/4-FULL tank at all times when we are probably only using 10-gallons per outing. We are only on local lakes, so it's not like we are 60 miles out to sea.

[Is there a] way to dip the tank and get a real measurement to know how accurate the gauge is?

[Can readers offer some] advice [about fuel tank level management]?

[jimh]

Congratulations on the nice day and evening of boating.

There typically is no ULLAGE PIPE on the fuel tanks of smaller outboard engine boats like a Boston Whaler 190 MONTAUK that permits sounding the tank for fuel level.

[jimh]

Re fuel tank level management: keep the fuel tank at least 1/2-FULL.

[jimh]

Re understanding fuel tank level indication and correlation to volume of fuel in the tank-- your implied question--I recommend the following procedure:

Burn off most of the fuel in the tank until the tank level gauge reads EMPTY.

Go to the fuel dock.

Begin adding fuel to the tank while observing the volume reading on the dispensing fuel pump and the reading on the boat fuel tank level gauge; at five gallon increments note both readings.

Make a table of fuel volume in the tank and corresponding fuel tank level gauge reading.

Post the table in a convenient place on the boat.

[Jefecinco]

Apparently you did not avail yourself of the Smartcraft gauge option with your 190. For peace of mind now and in the future I recommend you invest in the Smartcraft Gauge package. It will tell you the level of fuel in the tank with excellent accuracy. It will also tell you how much fuel you are using and how much you have used. If combined with VesselView which displays the information available in a user customizable gauge format you'll have an excellent engine, performance and fuel management system.

To answer your question, I refill our 190 after every outing at a non-ethanol fuel selling station or at the marina nearest the launch ramp I've used. This allows me to go virtually anywhere in our boating area and return without worrying if we have enough fuel in the tank.

Over the years I've towed several boats to safety. All of them ran out of fuel. I've also jump started a few but most boats needing assistance were out of fuel.

[Tacky79]

How about keeping a 5 gal jug on board and running it completely out while on the water, add the 5 gallons, then do the fuel-dock idea that JimH mentioned? I'm hesitant to run it too close to empty, even though our lakes are quite small.

I'll look into the smartcraft gauge pkg as well.. Jefecinco - do you happen to have a pic of your gauges? VesselView Mobile seems like an inexpensive way to get this data, but the circular SC100/SC1000 probably isn't too pricey either.

My Whaler dealer is mostly a Yamaha dealer, so I'm not sure how informed they are on the SmartCraft gauges, so I may have to do some research on my own. I'm assuming I don't have the Vessel View module or whatever transmits data to my phone or gauges?

Thanks guys.

[Phil T]

This is one of those things you learn about your boat.

Fuel gauges are unique and it will take time to learn its behavior.

You can start by keeping a log book with each trip, mileage and time (taken from the GPS) gas level start, finish, and how much fuel you added if any.

[Ridge Runner]

Most of the boats I have owned have the same concern that you mentioned, the first half of the tank as measured by an analog fuel gauge, last longer than the second half. My current 210 Montauk is no exception, with a 66 gallon fuel tank, at a measurement of half a tank left on the fuel gauge the boat will take about 42/44 gallons (about 2/3rd's of the tanks capacity) of fuel during refueling.

I find this is very consistent, with todays plastic fuel floats they do not absorb fuel and get heaver over time, so once your comfortable in understanding your boats fuel dynamics you should be in a good position unless the sending unit fails. As Phil has noted - just get to know your boat. I always will re-fill at half a tank, as measured by the fuel gauge, knowing that I have ~22/24 gallons (about a third of a tank) left in the fuel cell.

I would not run your modern fuel injected engine dry, the injector pumps don't work if there's even the smallest amount of air in them. Therefor it might be necessary to bleed the air completely from the fuel lines and injector pumps before the engine will start and run properly. Also, usually the fuel filter will prevent dirt from getting into the injection system. But on the other hand, the filter may not have enough capacity to prevent water from the bottom of the tank from getting to the injectors.

[andrey320]

What a coincidental discussion! I was going to start a thread but came to my own conclusions.
Same as Tacky79, I had a wonderful day out on our "Lake Pacifica" (Pacific ocean on the rare, super calm conditions) aboard my Dauntless 15. I fished in the morning at Anacapa and Santa Cruz islands. By late morning, I was done trying to catch Yellowtail and had enough Barracuda (~10 released) and a couple of nice kelp bass (including my personal best around 10lb). The conditions were so nice that I decided to take a ride to Painted Cave and the West end of Santa Cruz island which has been my goal for many years now. By this time, I had 40+ miles for the day. The ride and sightseeing were amazing but when I got in and checked the mileage and filled up, I realized that I severely violated the 1/3 reserve rule....

90 miles, 10.5 gallons of gas out of a total of 12.... The interesting thing is that I don't really have a gauge and just do the math in my head. I always fill up after every trip so I know I'm full. I knew it would be kind of close but didn't account for the trolling/idling and extra distance I did in the morning. I guess the call of adventure got the best of me that time but I won't let that happen again.

In the future, I'll be bringing an extra 5 gallon tank whenever there is a chance of weather being nice. The next goal is to circumnavigate Santa Cruz island.

[Dutchman]

I would not run your modern fuel injected engine dry, the injector pumps don't work if there's even the smallest amount of air in them. Therefor it might be necessary to bleed the air completely from the fuel lines and injector pumps before the engine will start and run properly. Also, usually the fuel filter will prevent dirt from getting into the injection system. But on the other hand, the filter may not have enough capacity to prevent water from the bottom of the tank from getting to the injectors.

Ridgerunner I know you're not supposed to run fuel injection dry but than BW would not have set-up my boat with 2 separate tanks. My little 2008 Montauk 150 has the proverbial 2x 6 gallon deck tanks under the RPS and I therefore don't see them. The two tanks are not inner-connected and so when I'm boating and one of the tanks runs dry (using my 2008 60 HP Mercury fuel injected 4-stroke) I drift to a stop and un-clip the hose, switch it to the other tank, push the prime bulb 2 or 3 times and start the engine back up. (I have to note I never use the prime bulb during regular operation (once every 1 or 2 weeks). Never had a problem with air entering the system she starts up within a couple of seconds..

I know what my engine uses (2-3 gph or less) and keep track of that in my mind and together with the 1/3 rule (1/3 to get there, 1/3 to get back, and 1/3 reserve) I never ran out of gas. Knock on wood (oh wait I don't have a 60th Anniversary Montauk which has wood option).

[Ridge Runner]

Dutchman - The major difference is that your 2008 Mercury 60HP outboard's EFI is accomplished by using a throttle body, and the Mercury 150HP outboard on the 190 Montauk uses a completely closed fuel system with sequential multi-port electronic fuel injection. It is not advisable to run fuel injectors dry.

[acg123]

I have a 22 gallon Moeller white tank under the RPS of my 1991 Montauk. I was in the same situation and always not trusting the tank cap gauge. So I did something similar to what was suggested above. At the start of this season, with an empty tank (I drained it in the fall for use in my snow-thrower) I went to the local station and added a couple gallons at a time and noted where the cap gauge responded. It took a while, but now I know the first hash mark is 4 gallons, the next is 9, the next is 14, etc. This has been great to know so I don't chance it, but I also don't make unnecessary trips to the gas station when I have plenty in the tank for my planned trip.

Also, make sure you note if the tank gauge responds differently when on a trailer on land, vs when the boat is floating level on water.

[Tacky79]

You guys might enjoy this....

I stopped into a Mercury dealer near my house. Mercury sign out front. Mercury parts hanging all over the place, mercury oil, fluids, filters, etc.

I asked the two guys at the counter if they had the VesselView mobile module for my 2017 Merc 150. The guys looked at each other, then at me, and said that they never heard of that. I went on to describe how it plugs into the port on the engine and lets you view all the info via smart phone. They had a look on their faces like I was from the future describing how I can transport myself via telepathy and cold fusion or something.

He said' he'd look it up if I had my serial number. I didn't have that handy, so I politely showed him how his point-of-sale computer could browse the internet and pulled up the VesselView Mobile website.

They were both very friendly, but not quite up to speed on VesselView. I won't hold it against them, as they were nice enough and accommodating and friendly, but it was an interesting exchange!

[Dutchman]

Dutchman - The major difference is that your 2008 Mercury 60HP outboard's EFI is accomplished by using a throttle body, and the Mercury 150HP outboard on the 190 Montauk uses a completely closed fuel system with sequential multi-port electronic fuel injection. It is not advisable to run fuel injectors dry.

Ridgerunner thank for the education I wasn't aware of that (difference) and understand now.
Bottom line is; get a Smart gauge setup so you know for sure.

[jimh]

Even old outboard engines with multiple carburetors don't particularly benefit from letting the fuel system run dry with the engine running. Each cylinder is fed by its own carburetor. When a cylinder runs out of fuel, it loses lubrication because the oil is in the fuel. With a multi-cylinder engine, not all cylinders will run out of fuel at precisely the same moment. Some cylinders keep running while others run dry.

[jimh]

TACKY--regarding a Mercury dealer who knows nothing about SmartCraft and VesselView:

I am not too surprised by your observation that a Mercury dealer is not familiar with SmartCraft and VesselView technology. Those technologies are usually found on the larger horsepower engines. Dealers that sell engines for small fishing boats probably don't encounter SmartCraft and VesselView very often. And Mercury does not provide public resources of detailed information about those products. Apparently they don't provide too many resources to their dealers, either.