2022 Mercury 150 Pro XS - wouldn’t start

[Bassooka]

I may have posted this in the wrong board last night. Posting over here now…


SN - 3B226826

Hey guys. Had a weird thing happen with my 2022 Mercury 150 Pro XS today. I took it out for the first run of the year after being winterized in December and recommissioned this week by my dealer/mechanic. For about an hour today it just wouldn’t start. It worked fine for several starts before that, and after that. But for an hour when I would turn the key it would beep when the key got to the first click (Run?), then I would hear a hum in the motor (fuel pump or fuel injector?)…both sounded normal. Then, when I turned it to Start, the engine would click; like for a fraction of a second the engine sounded like it was going to start, then it would stop and single beep again.

Vessel View mobile showed no codes, and the voltage was at 12.5. The battery was also just tested a few days ago and is also less than a year old.

Throttle and kill switch were where they should’ve been.

After talking to my dealer and trying a whole bunch of failed starts, I gave up and started to make the 2 mile trek back to the ramp with the trolling motor. At some point tried the key again. This time it tried harder to start, but was very labored and didn’t make it; it still got further than before, but sounded slow and ugly. I tried it again immediately after that and it started right up. I let it idle for about an hour or so. Eventually I turned it off and it started back up fine after that another handful of times. Of course, I didn’t venture far from the ramp.

Other info that may or may not be relevant -

In the morning the first start of the day was a little rougher than normal but not terrible. It also stalled once while backing it off the trailer, but the trailer wasn’t in deep enough so the boat was a bit hung up. It started right back up with no issue.

Also, when it wouldn’t start, I tried to push the throttle forward but it was very very hard to move. It was easy to move it back into the reverse direction, but forward it didn’t want to go.

The entire time the engine wasn’t starting the graphs still worked fine as did the trim.

It’s with my dealer now, but just wondering what you would look at if this was your boat?

Thanks all.

[EuropeanAM]

Likely a loose battery connection, battery switch connection, or keyswitch harness connection.

Would normally add "starter" connections to that list, but the repeated beep cycle tells me the PCM is "waking" a second time.

[Bassooka]

Thanks. The wires coming off the battery all seemed secure. The dealer mentioned wanting to check something with the key switch connection, so here’s hoping that’s it.

Appreciate the help!

[leonreno]

I may have posted this in the wrong board last night. Posting over here now…


SN - 3B226826

Also, when it wouldn’t start, I tried to push the throttle forward but it was very very hard to move. It was easy to move it back into the reverse direction, but forward it didn’t want to go.


Thanks all.

Don can correct me if I’m wrong but it’s best to not to push throttle forward when starting the motor, it messes with throttle position calculations and can cause it run bad or not at all.

[EuropeanAM]

You should not attempt to apply throttle OR shift unless the engine is ALREADY RUNNING, it's IN THE WATER, and you're planning to go somewhere.

[Bassooka]

You should not attempt to apply throttle OR shift unless the engine is ALREADY RUNNING, it's IN THE WATER, and you're planning to go somewhere.

Good heads up. Thanks.

My dealer went through the boat and checked every connection that could be causing this; he found nothing. He also started the boat a bunch of times and couldn't replicate it. I was worried about this.

He called Mercury and the tech he spoke to didn't seem surprised. The tech said he's heard of this exact issue many times before on this motor. He said the computer on this particular model is super sensitive to voltage, moreso than their other motors. This seems like a weird explanation because the battery was strong and the electronics were barely barely on, and we weren't stopped very long. Also, the problem solved itself. If there was a battery voltage issue, how would it self-fix? The tech told him to make the cords that run to the battery much shorter than they come from the factory. He said once they do that, this issue goes away. He also said that even if you don't do this it may never happen again. This all sounds odd and unsatisfying

I bought some paddles and I'll keep a jump starter onboard.

[EuropeanAM]

Battery voltage is believable, especially if the battery isn't WELL above the minimum specifications.

As for shortening cables: DO NOT. Once modified they're no longer covered (nor is anything else affected by the modification). I'll go far enough to say that I "doubt" that instruction was provided by Mercury Tech Service.

[Bassooka]

Battery voltage is believable, especially if the battery isn't WELL above the minimum specifications.

As for shortening cables: DO NOT. Once modified they're no longer covered (nor is anything else affected by the modification). I'll go far enough to say that I "doubt" that instruction was provided by Mercury Tech Service.

The advice to shorten the cable was provided by Mercury. I guess it comes with a 12 foot cable; he asks what they’d recommend if someone needed the full 12 feet and they said they’d recommend replacing with a heavier gage wire.

[EuropeanAM]

Wow. The later part is correct.... 12' max on that wire size. The earlier.... if done CORRECTLY it wouldn't be a problem but it's technically modifying it.