‘14 Prostar motor don’t start

[Timber]

2014 Prostar with 5.7l. Motor won’t start

Battery ok

Switch and kill switch ok

Fire on spark plugs ok

Fuel pump seems to work

After many trial to start the engine, spark plugs stay dry so seems no fuel in the cylinders

Any idea to continu my research?

[LoopSki]

Put gas in it! Lol. Joking but not really. Did you run it empty perhaps? I ran mine empty and even after putting 5 gallons in , boat wouldn’t start. Had to add another 5 and it finally fired up. Weird 2017 PS

[Andre]

''...fuel pump seems to work...''

Not good enough, put a fuel pressure gauge on the fuel rail.

[DW]

+1 on read actual fuel pressure, and purge any air at the schrader valve. Check oil pressure switch in case its defective and interrupting the fuel pump circuit.

[Timber]

Thanks @LoopSki! I just realized that my fuel gage is completely inaccurate ?

The tank was apparently empty but the gauge indicated 1/2!!! Lot of lost time but without the dealer fee ?

[chrislandy]

Mine reads empty with 3/4 tank then other times 3/4 full on vapours, don't trust the fuel gauge!

[MitchellM]

I'm not a current boat owner, but I've driven enough boats to realize that the fuel gauge is often inaccurate or broken. What is it with boats and fuel gauges? Seems like an important enough item to have working accurately!

[ProStah_Skiah]

Do you guys ever fill your tanks to full? The ProStar fuel sender estimates fuel level by measuring capacitance. Its accuracy can drift over time and is greatly affected by the ethanol content in the fuel from batch to batch. Adding just 5-10 gallons at a time can eventually become a problem.

 

The sender has a circuit in it that re-calibrates itself to back to full when you fill the tank. This usually works pretty well. But, having said that my sender went completely bad this year. I replaced it (5 min fix) and it works great now.

[skihacker]

I only recently learned of the "calibration" feature on that system, mine had gotten to the point it would report half as full, I usually only keep it around half and it's on a hoist so gas goes in 5 gallons at a time, last week I ran down to 1/8 and filled it to the top and it seems to be accurate again. I kinda don't love this system, we're not on a private pond so the fuel management system likely not an option either?

[wski1831]

I thought there was some kind of fix for the fuel gauge. Like a different sender? I’m filling with 5 gallon cans. Tough to fill and not overfill.

[wski1831]

Mines a 2017 prostar

[skihacker]

When I filled mine to the top I switched to small cans with a small spout once I knew I was close to full, with a flashlight I could see it coming up the fill tube and I could also hear it, the boat only goes to a gas station like twice a year.

[ProStah_Skiah]

I try to keep the level low and fill 5-10 gallons at a time, but fill to full a couple times a summer to make sure the gauge stays accurate.

 

If you switch between ethanol and non-ethanol fuel, it will be particularly problematic. The sender reading is proportional to fuel level and capacitance. Fuel with 10% ethanol has twice the capacitance as non-ethanol.

 

If you are inclined to use a multi-meter, the manufacturer (Centroid) will help you troubleshoot your sender. If you need a new one, they will also sell you one direct.

[chrislandy]

@ProStah_Skiah I filled mine to the brim a few times over the summer at a different lake, similar fuel (98 E5 - super unleaded in UK/France) and gauge indicated full. After a 5hrs skiing it was reading empty.

 

 

 

 

I must tell you now that I run 99% on LPG so the first 3-4hrs was using the 15gal of LPG and then it switches onto petrol. But it only took 5-10gal to fill the petrol tank again - but it wasn't a similar volume each time.

[ScottScott]

@chrislandy That is definitely a problem (malfunction) with the sender system

 

@ProStah_Skiah Filling to full occasionally isn't enough to keep it accurate. Unless you fill each time between a full fill with gas from the same tank at gas station, it can get off. Ethanol % can vary even between various tanks of 10%. 10% means it can be up to 10%. So one tank could be 7%, the next could be 9%. Thats enough to throw it off significantly.

 

This fuel sender system is just a very poor choice. I was going to say for a tournament ski boat, but there are probably many other vehicles this would be problematic in. If you have your own tank, and fill the boat up everytime that tank is filled, then you can use partial fillups. Thats about the only situation I can think of that it works well. For those, like us, that trailer their boat whenever used it works ok. I never fill partial, if I may need gas while out I go ahead and fill up. For those on a lake, especially a ski school or ski club....its a very bad system. I think the management system is a weak work around for a poorly chosen system. Instead of a workaround, how about choosing a system that works.

[LoopSki]

My gauge will peg out to full or empty when its empty. If the needle is moving I know I have fuel. Living on the lake , i dont worry too much If I run out. Usually only is a problem on a restart. Never ran out while underway.

[Andre]

What's so freaking special about boat gas gauge that it never work?

Car gauges have been reliable for 75 years...or more!

[Timber]

Thanks for all your comments. I will fill my thank completely this weekend. Indeed I’m on a lake for the summer season and I uses 2X 5gal at a time so this type of gauge it’s ineffective for me.

[tjs1295]

It is amazing how inaccurate gas gauges are. I disconnected the wire to the tank on my SN 196. It would always alarm around less than half a tank. Very annoying. Then I removed the panel inside the storage locker so I can just look at the tank. If I can't see the gas level, I know it's time to add. Did the same thing with our old 1994 SN. Always lifted the backrest to look at the level. Not sure if that's an option on the newer boats, or other brands.

[UWSkier]

Can you replace the sender with a float style? One of the benefits of my boat rebuild last year was an opportunity to index my fuel gauge against tank levels. I went to the gas station and started filling the boat in 5 gallon increments, then turning on the key to get a read. The logic on this gauge is that it will read the level on key-up but then it goes into averaging mode so sloshing doesn't effect the gauge.

 

It's a 35 gallon tank in my Response. These are my gauge references. Somewhere between 10 and 15 gallons was where my needle moved off E. I keep them in a google photos album called "FUEL LEVELS" so it's always easy to find.

 

 

[ScottScott]

@UWSkier That won't work with the 2014+ Prostar system

[UWSkier]

@ScottScott will the dash unit/gauge not accept an input from a normal float sensor? I'd expect that the current sender measures capacitance, then converts that to a common signal that can be deciphered by a standard dash, no?

[ScottScott]

I suppose that may be possible. Not easy....but potentially possible.

 

[BraceMaker]

Interfacing to the factory gauge tough - doing an aftermarket gauge with a float is super easy.

The newer gauges have capacitance readings not ohms where as the older senders are just a variable resistance ground.You could easily swap the factory sender and install a second gauge. But the 2014+ version gives a voltage output from 0-5 volts and are 3 wire where as the older mechanical units are ohm based and vary resistance of the ground path of the gauge.Just different systems.

 

[skimtb]

reading thru this wondering if I should still use non ethanol at end of year, as it feels better to have that sit in all winter (6 months or so). I run ethanol / 89 all summer. Is is bad for fuel gauge to do that? Worse than leaving the ethanol fuel sit all winter? I try to run close to empty, so less old fuel in spring.

 

[jpwhit]

I run ethanol fuel most of the time, because as long as it doesn't sit for a long time it helps keep water out of the tank. And in newer fuel injected boats, the fuel system is designed to stand up to ethanol fuel. I do put non-ethanol fuel in for the boat when I'm not using it during the winter. But for me, that's just mid-November through February. Ethanol fuel isn't nearly as stable as non-ethanol fuel over time. The ethanol tends to absorb and retain moisture. But you should always fill the tank for winter storage. If the tank isn't full, then there is a lot of air in the tank. The air exchanges through the vent and can cause condensation in the tank during the winter temperature changes. A full tank prevents condensation during the winter. If the fuel level is really low, then metal components in the tank, such as the fuel pump assembly can corrode if they aren't submerged in fuel. I do run non-ethanol fuel exclusively in any engine that have a carb. Such as all my lawn equipment. If I had a boat with a carb, I'd run non-ethanol all the time.

 

[Broussard]

Not bad for the fuel gauge, just need to fill the tank completely with the boat powered off in order to calibrate the fuel gauge sending unit.

 

[Mastercrafter]

just to confirm.. do all 14-20 Prostars work like that.. fill (full) with power off to calibrate? Are you supposed to fill to full with power off every time, or does the calibration last… until it doesn’t? What happens when you use 8 gallons but add 5?

 

[Broussard]

As far as I know, yes. They should all have Centroid electronic fuel sending units.The best course of action is to fill completely with power off as often as possible as any fluctuation in ethanol content percentage will affect the accuracy of the reading. In your example - if the additional 8 gallons are the same exact variation of fuel (say from a 500 gal tank you have at your lake) it should be no issue. If you add 5 gallons from the local station which has 10% ethanol, but you calibrated with fuel that had 8 or 9% ethanol you will have issues with accuracy."This is Joel, an engineer at Centroid Products. We make fuel senders for MasterCraft. I'll give some background info and then hopefully do some science with y'all to figure out what's up.

 

We make fuel senders that measure capacitance between their two concentric tubes. The more fuel there is between the tubes, as opposed to air, the more capacitance and the higher the reading. There's a microcontroller in the sender's head to convert the capacitance into a Send voltage for the gauge. The selling point is no moving parts in the sender. Plus the microcontroller lets us do averaging of the output to smooth out chop, and MC has us doing 12 seconds of averaging.

 

Ethanol in gasoline complicates things for measuring capacitance, though. Gasoline with 10% ethanol has twice the capacitance(!) of gasoline without ethanol, and the percent can be anywhere between 0-10%. To correct for this there is a Full Detection stinger in the top couple inches of the sender to detect when the sender has been powered up with a newly filled tank and correct the Full cal if needed."

 

https://www.ballofspray.com/forum#/discussion/18004/gas-gauge-on-new-prostars/p1

 

 

[ScottScott]

It still amazes me that MC has stuck with a system, FOR 8 YEARS, that just isn't practice in this application. When properly calibrated, it is an extremely accurate system. However, very few people that own this boat use it in a situation that maintains calibration.

[Broussard]

@ScottScott Supplier decisions are typically made at a higher level than just ProStar. MasterCraft is very likely using Centroid fuel sending units across their entire line. In the larger boats trailering and filling the tank completely is much more common.

[Mastercrafter]

@Broussard thanks for the info. I was not aware that's how they worked, and it's interesting that they have a "reset" switch when full for calibration. Now I know.. and now I know why my fuel gauge seemed to stop working well.. while still working.

[epnault]

When I got my boat I was having issues with my gauge and talked to MC and the supplier. They told me to not top off fuel when it is above 1/2 tank and always power off the boat with the master switch in the electrical panel. When you refuel make sure it is still powered off and fill it full before you power on the switch and start the boat. Haven't had any issues with this procedure

[Minelickskier]

Every prostar I have owned has had a disfunctional gas gage. It has caused lots of inconvenience. Crazy that this has been at least a 25 year trend with mastercraft. It just doesn’t seem like rocket science….

[skimtb]

Good info here, thanks.@jpwhit I think I "learned" on MC teamtalk that the plastic fuel tanks are less likely to suck in moisture than the older metal ones? I've been running boat to 1/4 for quite a while now for winter storage.

Agree this is not an ideal solution for those adding 5-10 gal at a time vs filling up, or don't want a full tank ever, but see the point the prostar is low on the total MC list for "common" component selections....

[BraceMaker]

@skimtb it's not sucking in. Both tanks equally in and exhale air.... but metal will condense out water on the inside of the tank. Think about like a beer can vs. A plastic cup but backwards.

[skimtb]

@BraceMaker Makes sense thanks. Although your analogy has me off track now.

[jpwhit]

Right, as barometric pressure changes, air is sucked into and pushed out of the tank. The air being sucked in brings in the moisture that's in that air. It's a tiny amount, but the longer the boat sits unused over the winter, the more water that accumulates.

I can see that a metal tank will tend to condensate more than a plastic tank. Even without condensation, if you have ethanol in the tank it will absorb the moisture out of the air. The fuller the tank, the less air volume in the tank. The smaller the air volume the less air to expand and contract and therefore less air that flows in and out and brings in moisture. Liquid gasoline does not expand and contract with barometric pressure. And the change in volume of liquid gasoline with temperature is inconsequential.

I almost never fill my tank either to keep the weight out of the back of the boat. But winter is one of the few times I do. In the spring, it doesn't tank long to burn off the extra weight and I'm not going for a PB first thing in the winter anyway.

But if you've been doing it a different way for a while and haven't had any water in tank issues. Then it's not really an issue. Actually, since you said you run ethanol fuel during the season, that will clear the water out over time. This is more of an issue for folks that run ethanol free all the time.

[BraceMaker]

@jpwhit so I run it low then switch to non-ethanol rec gas, fuel stabilize it, burn as much down as I can.

Then I take good tape and cover the vent for the winter.

I've debated installing a ball valve in the vent line for that purpose, it cannot be a check valve or you'll draw a vacuum when running and eventually kill your fuel pump so you would have to open it for season.