2021 mercury 4 stroke 115 not turning over

[Kmpcfp]

We have had this boat out about 6 or 7 times, we bought it used with 4 hours on it and have had no issues with it until we went to start the engine (2021 Mercury 115 4-stroke) after being anchored and could not get it to turn over.

It would crank and occasionally spit water, but it would not actually turn over. Battery meter was reading 12 volts at the dash, we had 3/4 tank gas.

Got home hooked up the water inlet and let it run, started engine and it started right up. Turned it off let it sit for a few minutes and it started back up again. I plugged in the battery charger and it read it was at 50% capacity.

Could it be that at the time we tried to start it on the lake it just didn't have quite enough battery to fully turn it over or is it something more major we need to have looked at?

 

[ThomW]

When you were anchored, were you listening to the radio or have any other accessories on? It very well could have been the battery didn't have the juice left to crank it over. That's one reason I always run 2 batteries with a switch. Charge you battery and bring it to the water and see. If it's a 2021, with very few hours, it shouldn't have any issues. Did you follow the break in procedures for the motor as far as what RPM"s to run it at for the first several hours?

 

[Kmpcfp]

When you were anchored, were you listening to the radio or have any other accessories on? It very well could have been the battery didn't have the juice left to crank it over. That's one reason I always run 2 batteries with a switch. Charge you battery and bring it to the water and see. If it's a 2021, with very few hours, it shouldn't have any issues. Did you follow the break in procedures for the motor as far as what RPM"s to run it at for the first several hours?

Thanks for the reply. We did have the Bluetooth/speakers on while anchored. What confused me though is when we got home, it started twice with the hose in the water inlet without a problem before I even plugged the charger in.

We kind of assumed the previous owner did the break-in procedures during the time he had it. (The first 4 hours). The dealer had possession of the boat and winterized it until we bought it this spring.

The manual says "for the first two hours run the engine at varied throttle settings up to 4500 rpm or at 3/4 throttle, and at full throttle for approx one minute every ten minutes"

The next step, we have followed:

"For the next 8 hours of operation, avoid continuous operation at full throttle for more than 5 minutes at a time".

 

[emilime75]

Not sure what your problem could've been, but it sounds like you used the hose connection intended to flush the motor out when you ran it at home. This, in theory, should keep the motor cool, but it doesn't lubricate the water pump impeller in the lower unit and you could burn it up. Best to use ear muffs on the water intake if you're going to run it out of the water.

 

[QBhoy]

Hi. If you mean it was no more than exactly 12v. You’d struggle to start that engine. They either will or they won’t. I’ve one and there is nothing in between. If you mean it didn’t turn the engine over at all..it might have been in gear. But it wouldn’t crank at all like that. You need to have about 12.5v to begin with befkre it would likely start. Anything closer to 12.0…it’s unlikely to start. These modern engines just won’t even bother trying to fire..unless all their sensors and ecu detect enough to power them all.

 

[Alumarine]

If you're asking would not following the written break in procedure explain your starting issue? The answer is no.

Like others have said it could be a low battery.

fyi cranking and turning over mean the same thing which is the motor is rotating and trying to start. It does not mean the motor has started.
Do you mean the motor "cranks" but doesn't start?

 

[QBhoy]

If you're asking would not following the written break in procedure explain your starting issue? The answer is no.

Like others have said it could be a low battery.

fyi cranking and turning over mean the same thing which is the motor is rotating and trying to start. It does not mean the motor has started.
Do you mean the motor "cranks" but doesn't start?

Have another read fella. He said it cranks but doesn’t turn over. That’s why I’m trying to clarify. One and the same !

 

[Kmpcfp]

I am pretty sure it was the battery. The problem hasn't happened again since fully charging.

 

[QBhoy]

I am pretty sure it was the battery. The problem hasn't happened again since fully charging.

Excellent. Thought it might be. Happened to me with this engine too.

 

[Alumarine]

Have another read fella. He said it cranks but doesn’t turn over. That’s why I’m trying to clarify. One and the same !

I was directing my comment to the OP.
To clarify what I meant. Cranks but won't start. Turns over and won't start. Same thing.

 

[QBhoy]

I was directing my comment to the OP.
To clarify what I meant. Cranks but won't start. Turns over and won't start. Same thing.

Got you.

 

[Kmpcfp]

I just wanted to give an update in case anyone else has this issue with this engine. We just got back from attempting to take it out. We fully charged it two uses ago (after the last time it died) and out of paranoia did not run any auxiliary powered things since charging. We got about 200 feet from the marina and the engine died while trolling. When attempting to start the engine back up, it would keep cranking, but would never start. The marina owner took a quick look over on the water to see if he could jump us on the water before towing us, and he came to the conclusion the engine wasn't getting any fuel. We are taking it in this week to get it looked at. Hopefully this is an easy fix and is covered under warranty.

 

[RMClark]

Hope it all gets worked out at the dealer.

I noted your discussion about the break in period, and that perhaps the previous owner had done it during the first four hours of operation. Mercury's web site outlines a 10-hour break-in period and states it is similar for most Mercury outboards. You may want to look into that.

Good luck.

 

[Kmpcfp]

It turns out it was a faulty fuel supply module, which seems to be a semi common issue for this engine. Luckily covered under warranty.