mercruiser 5.0 mpi cuts out after it runs for an hour

[jmc830]

I have a brand new four winns finship with a mercruiser 5.0 mpi it has 20 hrs on it whn i run the boat during the day in heavy boat traffic where there is a lot of stopping and starting putting a load on the motor after an hour the boat just shuts off doesnt spit or sputter just like someone turned the key off it i can start it right back up and idle i can put it in neutral and rev it but when i get up on plane it shuts right off let the boat cool down it will drive again until entire motor reaches a certain temp not the operating temp but temp of entire motor been to the dealer 2 times this time been there for two weeks dealer said they cant get it to do it so they cant replace anything they have only driven it for 30 minutes i think it is the ecm doesanyone have any input

 

[Dunaruna]

Re: mercruiser 5.0 mpi cuts out after it runs for an hour

Hi jeffmc,<br /><br />Wow, take a breathe.<br /><br />Brand new means warranty, they need to take it out on the water and test - their problem not yours. Don't accept 'can't find it'.<br /><br />Did it log any codes? Is it overheating? The list goes on and on.<br /><br />Aldo

 

[jmc830]

Re: mercruiser 5.0 mpi cuts out after it runs for an hour

the computer posted no codes they water tested it for 30 minutes they could not get it to do it the first time the said they adjusted the neutral cut off switch it stranded me it will idle but put any load it will just shut off i told them it sound like a ecm or a ignition module if a mpi has a module they sed they couldnt replace anything unless they could see it happen for themselves tested it again on tuesday but sed they wold not got to it again till next week

 

[steve n carol]

Re: mercruiser 5.0 mpi cuts out after it runs for an hour

sounds like a fuel filter to me.

 

[hoot]

Re: mercruiser 5.0 mpi cuts out after it runs for an hour

i would be talking to the mgt of the dealership, fourwinns, and calling merc. usually heat gets to electonics over time. other things are vapor lock, undo fuel cap and see if anything happens. check fuel vent for plugging. next time it happens to you, pull a plug wire, hold close to plug and start motor. watch spark intensity. is it carbed? remove spark arrester and give it some gas. does any squirt in the bores? fi? don't know how to check for gas here.

 

[jmc830]

Re: mercruiser 5.0 mpi cuts out after it runs for an hour

just a little update after 3weeks the dealer said mercruiser finally authorized an ecm they said there was a service bulletin on the problem i am having will try it this weekend when its hot out with lots of boat traffic i'm crossing my fingers ha ha