merc 40 hp 4 stroke

[toolsinbox]

I have a merc 40 hp 4 stroke I think is a 2002. i had some battery probs and borrowed a bat to re- start and wanted to remove it to put back old one just to get home. As soon as I disconnected the good battery engine stalled.

Should the engine run by itself not connected to a battery?

 

[sxmerc]

Re: merc 40 hp 4 stroke

Is this motor fuel injected?

 

[toolsinbox]

Re: merc 40 hp 4 stroke

im not sure. I think it is. What would be the difference may I ask.

Clearly the generator (or alternator im not sure) on this outboard will not run the engine by itself. It is either designed that way to just provide a small amount charging for the battery or it is not working correctly.

 

[sxmerc]

Re: merc 40 hp 4 stroke

The motor should stay running with no battery regardless if it's a carb motor or EFI. The reason I ask, if you have an EFI motor that has something wrong with the charging system and then disconnect the battery, it will die. An EFI motor needs voltage from somewhere to stay running, a carb motor does not. With that said, you should never remove or disconnect a battery from a running motor as you can do damage to the charging system. So, if the motor is EFI and died when you disconnected the battery, I would say you have a problem with the charging system.

 

[toolsinbox]

Re: merc 40 hp 4 stroke

Thanks for that heads up. will have to have it checked out. any tests I can run to narrow things down?