motor stuttering after turning off the boat. what causes this?

[macr6]

Question is in the title. I have a 98 4cyl 3.0L merc. When I turn the key off the boat still stutters for a couple seconds. Just like our old family cordoba used to back in the day. What causes this so I can fix it?

 

[Fireman431]

Re: motor stuttering after turning off the boat. what causes this?

Tune up.
Timing
Dwell.
Better Gas.

 

[ziggy]

Re: motor stuttering after turning off the boat. what causes this?

just found this looking thru some sb......
http://www-alt.mercurymarine.com/mnetdata/Service/Cruiser/Bullet/97/Sb97_17.pdf

 

[thumpar]

Re: motor stuttering after turning off the boat. what causes this?

It can also be carbon build up on the heads. It holds heat and builds just enough compression to ignite the mixture.

 

[Don S]

Re: motor stuttering after turning off the boat. what causes this?

It can also be carbon build up on the heads. It holds heat and builds just enough compression to ignite the mixture.

While that is a strong possibility on an automotive engine, marine engines seldom build up that kind of carbon. Just the rpm range the run in prevents it.

 

[JustJason]

Re: motor stuttering after turning off the boat. what causes this?

double check your idle rpm

 

[macr6]

Re: motor stuttering after turning off the boat. what causes this?

just found this looking thru some sb......
http://www-alt.mercurymarine.com/mnetdata/Service/Cruiser/Bullet/97/Sb97_17.pdf

Thanks Ziggy.

I did put a new throttle lever on the carb and may not have the screw turned out right. May need a tune up. I will try these things this weekend. Hopefully it will not be a hundred degrees like this last weekend.

I believe that the few times it did it, the boat was shut off quickly after coming to a stop.

 

[chiefalen]

Re: motor stuttering after turning off the boat. what causes this?

last post is right on point.these carb. motors need to run at idle about a minute or 2 after running hard.also when starting need to pump the trittle a bit to get the choke to close and get gas to it.good luck.