Starts smooth, then rough, dies

[AGolden]

2015 Mercury 4 stroke 90. starts up smooth then 1 second later shakes violently at idle and dies 90% of the time.
Put boat in water this morning, started smooth and as we idled through the no wake zone. It started shaking like something was on the prop. Checked, it was clear. The shake got worse as we headed back to the dock and died.
Has anyone had this issue?

 

[jimmbo]

Welcome to iboats

Carbed or FI?

 

[AGolden]

FI

 

[AGolden]

thanks for replying.

 

[brodmann]

Sorry, a lot of us here are old school 2 stroke carbed motor guys. No experience with 4 stroke fuel injected motors.

 

[QBhoy]

Hi. Have a look at the shift switch down the starboard side lower cowl. Just under the throttle and gear cables. There is a known issue with this, on these early models of the 2.1l engine. If that’s what it is. There is also a situation where the throttle assembly mechanism down there needs re adjusted to spec also. It’s in the manual now to do this and there’s also a device bulletin about how to do it too.
Might be worth mentioning that if for any reason you have the trim or tilt up beyond a certain level whilst this is happening (perhaps in shallow water)…the engine will not allow throttle beyond a certain rpm and will electronically limit things. This effect can also be known, should the neutral safety switch be failing you in the control box. It thinks it’s in neutral and will also limit the rpms to about 2500 rpm or less. Shaking considerably is seen during all or any of the above mentioned