Motor runs rough and won't start with electric start

Rsb1970

Seaman
Joined
Dec 29, 2016
Messages
59
I have a 2006 25hp Mercury EFI, tiller . I took it out last week and it ran great. Took it out today and it would not start using the electric start button. Had to pull
Start it. It ran good for a while but then it started losing power and would cut off.
Idled real rough. I would pull start it again and it would run good for a minute and then lose power again. When I pushed the start button it would click but wouldn't start. First boat I've owned. Any ideas on what is wrong? Thanks.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Okay, as for the electric start problem. That easily could be the battery, starter solenoid or the starter itself. A good way to trouble shoot those issues is by jump starting the solenoid with a jumper wire or even from from the battery directly to the starter itself. If that turns the starter, you have a bad starter solenoid OR the wiring between the battery and starter. If that still does spin the starter, check the ground wires first by cleaning them at each connection to bright shiny metal and reconnect. If that still doesn't spin the starter, you could have a bad battery. You can have that tested at most any auto parts store.

As for the hand pull cranking and running for a while and stopping again. That could be the fuel system from the tank to the primer bulb to the fuel pump and carb(s). Or even the tank vent is closed.

When you get it to run, can you hand squeeze the primer bulb and keep it running? If so, you could have a fuel pump issue.

Let us know what you've found out from those ideas and report it back here. JMHO
 

Rsb1970

Seaman
Joined
Dec 29, 2016
Messages
59
Ok. I went out and cleaned the battery connectors. They were a little rusty. Put them on the battery and pushed start button and it started right up. And the vent valve on gas tank was closed half way. So I will check and see if that was the reason it was running rough.
 

Rsb1970

Seaman
Joined
Dec 29, 2016
Messages
59
Just had a chance to take boat out. It started right up with electric start and ran good for a little while but then started losing power. I would turn throttle down and back up and it would gain power sometimes. I would pump gas bulb and it would go. So I don't know what is wrong. Guess I'll have to take it to a mechanic.
 

Rsb1970

Seaman
Joined
Dec 29, 2016
Messages
59
Finally got my boat to the mechanic. They said it had a leak in the fuel pump and getting gas in the oil.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Gas in the oil? That says this is a four stroke motor just like the one in your car. Be aware that gas in the oil will kill an engine and you will not like the repair costs. Just like your car, check the oil BEFORE every trip and do the sniff test. If the oil level is rising and the smells like fuel, determine why and have it fixed before running the engine. Gas is not a lubricant. It washes lubricated parts and they fail ---- expensively.
 
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