New Prostar - Fuel Gauge Issue

[JackQ]

@Broussard I stand corrected.  I did not know they used that method, as dielectric constant of ethanol is 10X of gasoline it would make a significant difference.  However, Mastercraft may have picked an elegant and complicated (and likely expensive) solution for a simple problem.  The “old school” mechanical sending units were prone to fail occasionally ( I have had one fail in 25+ years) but they operate  very consistently vice the problematic issue many MC owner have been experiencing.  

[jpwhit]

I use Fuel Management on my 2019 ProStar and I have to drive a couple of miles to get the course. It works perfectly. 

[ETskier]

My 47 ChrisCraft has the best gas guage ever. An original factory supplied 4 ft long measuring stick you put down the fill pipe. 75 years old and still works perfectly.

[lpskier]

@ETskier I was going to say the same thing. A stick in a level boat gives an accurate reading 100% of the time. And it has the added benefit of not needing an engineer either to build it, calibrate it, interpret it or repair it. Works like a beauty in my 1915 Lawley launch. 
 

As you may know, the 1947 model year was, I believe, the first post-war model, released in late 1946 after Chris Craft ceased war production and returned to recreational boat building. I have a 41 Chris Craft, “Skidaddle,” one of the last pre-war boats. The stick also works on this boat. 

Edited June 19, 2023 by lpskier

[vtmecheng]

With fuel management system active, fill to the top, you can see when full by pulling the rear storage bin on either side. Once full, turn on key, go to the fuel management system screen, tell it the tank is full. From then on just tell it when you add gas and how much. Not hard and it will work. I still hate that system over old floats, needless complication.

[Mastercrafter]

Can software be updated on a 2015 to include fuel management? 

[jpwhit]

27 minutes ago, Mastercrafter said:

Can software be updated on a 2015 to include fuel management? 

Hmm, I didn't know it wasn't included in 2015. Are you sure it's not just turned off in the setup screens. If it's really not there, then yes I think updating to later firmware on the screen would enable it for you. 

[OldGuysRule]

I've owned 4 Mastercrafts over the past18 years!  The fuel gauges were a mystery to me.  The 2021 that I have now seems to be the most accurate.  I do not use the "fuel management" option...just the regular percent of fuel in the tank.  And...for reassurance, I just lift up the middle step in the rear and look at the fuel level in the tank to be sure!

[Laz]

Thanks for the replies.  I’ll give the fuel management system a try.

[ScottScott]

This is the absolute DUMBEST technology for a fuel gauge to put into a ski boat (of all things.) The same grade gas from the same service station from tank to tank (station tank fulls)  can vary in ethanol enough to throw the whole thing out of calibration. The ONLY way to keep this accurate is to fill to full EVERY TIME. OR, at least fill up, then fill all of your 5 gallon jugs at the same time from same tank full of gas at the gas station. Then as long as you're putting in gas from that same tank you should be ok for partial fills. Once they get a new tank of gas, it could all change. 

The only thing dumber than this system, is that its been this way at least since 2014 and they have kept the same ridiculous system this whole time. The fuel management system they put in place is ridiculous. If the system doesn't work, then replace it with a system that does. This workaround BS is pathetic. 

I'd REALLY be pissed off if I lived on a lake and used 5 gallon jugs to add gas. At least since I trailer everywhere, I just fill up completely every time and have only had issues a couple times. 

[dave2ball]

@ScottScott please don't hold back. Tell us what you really think.  

Edited June 19, 2023 by dave2ball

[Andre]

Why does a gas gauge work in a car and not in a boat is a fascinating mystery for me.

 

[Lars]

@ScottScott I tend to agree, my '97 Sea Ray 175 had a gas gauge that was as accurate and stable as a car. 

[Bufootin]

It’s not just MC that can’t figure out an accurate fuel measurement system.  My 2022 Response TXi fuel gauge is crazy inaccurate.  Make matters worse, there’s no way to actually see the fuel level left in the tank as the tank is completely enclosed in the rear of the boat.

[braindamage]

Bump…

I just bought. ‘22 Prostar. I’m new to MC, so I was surprised when I learned of this silly fuel management system.

I was out yesterday and started with 93%, skied 4 sets and it went to 78%. Suddenly it plummeted to 3%. I immediately checked the back tank under the step and the fuel is approximately 1-2” above the top of the fiberglass from the step.

questions:

1) does anyone have a description of how much fuel is in the tank from visual inspection under the step? Is 1-2” the “bottom” of the tank? Im thinking of printing stickers or simply marking how much fuel is in the tank with a sharpie.

2) how could it go from 78% to 3% in a moment? Is this normal?

3)has anyone installed a manual fuel sender to an analog gauge to avoid all this silliness?

[blakeyates]

On 6/18/2023 at 9:56 AM, lpskier said:

We can build a boat that knows how fast it is going within 1/100 th mph and knows within 2 cm of where it is in the course, but engineers still can’t build a fuel gage for a ski boat that is worth a damn. 

💥 

[vtmecheng]

I just did this a few weeks ago with our 2021. Pull the back center step and the tank has a left and right side (obviously connected). Place a tape measure on a side with the hook on the bottom. Mark the following with a sharpie. These are fairly close based on knowing the size of the tank, filling in known quantities and measuring at each, and fitting with a best fit line. Luckily the tank cross-sectional area is nearly constant with height. In reality the cross-section of the top of the tank gets smaller so the top bit goes down faster. Let me know if you have questions.

1/4 full = 1 7/8 in

1/2 full = 3 3/4 in

3/4 full = 5 5/8 in

[RAWSki]

You dont have to use the fuel management system we disabled it in the settings and it works pretty well as a plain ole fuel gauge but still use the visual inpection method at times.  

[vtmecheng]

8 hours ago, RAWSki said:

You dont have to use the fuel management system we disabled it in the settings and it works pretty well as a plain ole fuel gauge but still use the visual inpection method at times.  

We tried that and it went way off fairly quickly. We tend to get gas from different stations and ethanol changes throughout the year here. That all means the ethanol in our tank can change a lot each with each fill.

[rico]

it is a mystery tome too. seems like a basic feature. I use a direct look at the tank under the step method because we cannot trust the gauge. most of the time the gauge goes to 100% after I add fuel, regardless of how much I add. 

The fuel management system is fine and maybe I should start using it again.

[wski1831]

I tried emailing Joel at centroid about my 2017 fuel gauge sending unit and it bounced back. Does anyone know what the part number for the updated or old sending unit is.

[Horton]

@Broussard ?

[skihacker]

Sku 150979 at inboard garage according to there site, maybe call first and double check. 

[Broussard]

@wski1831 direct message me your HIN, and I should be able to look it up

[VONMAN]

You have to love technology, but why reinvent it if it works? My 32 year old boat's fuel gauge still working after all these years.