2016 Mercruiser 4.3 MPI stalled while tubing; cranks but doesn't start

[Jimwhall]

I had replaced the battery earlier in the afternoon. Once I did it started fine. It was a little boggy off the initial holeshot but it was me and 7 kids (8th grade/sophomores) in my Four Winns H190 so I figured it was just weight. Towing hole shot was great. No problems starting after changing tubers.

I took a semi-hard right turn (people leaned, nothing flew out) to get the kids out of the wake and the boat just stopped. It cranks fine, but acts like there is no spark or gas. I had to get towed in.

Prior to that I'd been watching oil pressure and temp and both were fine. We were in 50 feet of water, and didn't hit anything.

Any thoughts? I'm flummoxed.

 

[bman440440]

did you check your emergency lanyard?

 

[Jimwhall]

did you check your emergency lanyard?

Yes. The way this engine cutoff works is if the lanyard isn't hooked in the engine won't even crank.

 

[achris]

Is the 'dead-man' switch connected, and maybe tripped?

 

[Jimwhall]

Is the 'dead-man' switch connected, and maybe tripped?

It was. But the engine won't crank when it's tripped. I will double check though; this boat is new to me so hopefully it's something that simple.

 

[Jimwhall]

I just transitioned from a 112 Johnson SPL; I used to run that on the muffs all the time. Is it safe to run an engine as big as this on the muffs?

 

[alldodge]

When key is turned ON does the fuel pump prime and hear 2 beeps?
When cranking does the Tach show at least 300 rpm?

Yes its fine to run on muffs

 

[Jimwhall]

When key is turned ON does the fuel pump prime and hear 2 beeps?
When cranking does the Tach show at least 300 rpm?

Yes its fine to run on muffs

Yes to the fuel pump and 2 beeps. I honestly don't know about the tach; I haven't looked at it while cranking. I'll check it out. Thank you!

 

[Jimwhall]

So when I got the boat the previous owner would take the lanyard out of the dead man switch all the time. I started leaving it in, but the first couple starts I'd have to kind of press it in to get the engine to crank; otherwise it would act like a worn down battery (enough power to get the solenoid to click, not enough to crank the starter)... It stopped doing that after a little while, but I'm wondering if the dead man switch itself might be broken or wearing out. My previous boat dead man switch would allow the boat to crank, it just wouldn't run. It's just really odd to me because it's acting like it either has zero spark or zero gas. Cranks freely... I guess it could be compression but this is a relatively new, relatively low hour engine that has great maintenance records.

 

[achris]

Something sounds amiss...
Deadman switch is designed to kill ignition in the event of the switch being flipped. Ignition dead, START circuit still active.
Neutral safety switch will stop the engine being cranked when the control isn't in neutral.
And the 2 do not interfere with each other, and you can have both at the same time.

Have you checked for voltage at the coil positive? (That would be the first place I look)...

Chris.........

 

[Jimwhall]

Something sounds amiss...
Deadman switch is designed to kill ignition in the event of the switch being flipped. Ignition dead, START circuit still active.
Neutral safety switch will stop the engine being cranked when the control isn't in neutral.
And the 2 do not interfere with each other, and you can have both at the same time.

Have you checked for voltage at the coil positive? (That would be the first place I look)...

Chris.........

I have a multimeter I just bought but no idea how to use it.

So, just so I'm clear:

Deadman switch is attached to the Lanyard. Switch connects to the 'RUN' toggle. Problem here means engine cranks but doesn't start.

NSS is connected to the actual throttle lever. Problem here means engine doesn't crank.

It does 'pause' when I go from neutral into gear. It's almost like the engine stumbling. But I thought that was a feature.

 

[alldodge]

Some of the newer VP will keep it from cranking, but have not heard where Merc is following suit

 

[achris]

...
It does 'pause' when I go from neutral into gear. It's almost like the engine stumbling. But I thought that was a feature.

You have a shift cable problem...

It's holding the shift interrupt switch closed and stopping spark.

Chris...

 

[Jimwhall]

You have a shift cable problem...

It's holding the shift interrupt switch closed and stopping spark.

Chris...

Please tell me that's cheap to fix.

I replaced the shift cables on my old Sylvan, wasn't that big of a deal at all (it was humorous as when they went out I was stuck in reverse and had to reverse home...)

But.... things were much easier to get to on the Sylvan.