2003 Mercury 40 hp

[BillyBoy23]

Hey guys,

I looked over the post on the 25 Merc but I think my problem is a little different.

This is the first boat I have owned and don't by any means consider myself a handy man. I have called around and spoke with friends about what they think may be wrong but want some tips from the fishermen type.

When I put the boat in the water after sitting for a few days the engine has a hard time idling. When I put the boat in the water I trim the engine down, pump the gas ball and prime the engine 3-5 ( by pushing the key in ) 8/10 the engine will start on the first turn but as soon as I put the throttle back into neutral the engine dies. It seems like it doesn't get enough gas to idle on the first start.

So what I am ending up doing ( which I think is bad ) is choking the engine and pushing the throttle way to far forward which causes the engine to rev to around 4000 rmps then I throw it into neutral and back into forward and take off so the engine won’t die.

What is strange is after I take my first run across the lake the engine will run great the rest of the day. That makes me think that something is building up over the few days it sits then I work it out with the first run and it is cleared the rest of the day.

Lastly the hole on the back of the engine that shots out the water that cools the engine also hesitates the first start. Water is coming out however it is not a constants stream. But again once I take my first run and the water sprays out just fine the rest of the day.

I have tips from dealers to run sea foam thru the engine. Also that the fuel filter may be clogged. Or that the carbs need cleaning

Any other ideas?

Anything would help and i may have to ask more questions because I don’t know much about engines.

Thanks

-Bill

[marine_man]

Is this a 2 stroke or a 4 stroke?

To summarize your question (or my interpretation anyway) is that you have a motor that's hard starting the first time, correct?

Your startup procedure is pretty much right on, except for pushing the choke in 4 times to prime the engine. If your motor is a 2 stroke you have a choke, not a primer. Pushing the key in closes the butterfly valve in the carb for the choke, so what you want to do is push the button in and crank at the same time.

Advancing the throttle to start a cold engine is common. If you're concerned about the rpm's you could back off on the advance a little bit, but you're not outside the realm in my opinion.

The other thing you can do, while the engine's warming up, is when the engine is about to die push the key in again and release it to keep it from dying.

marine_man

[MuskieJunkie]

That's just how those engines are, seafoam will help, getting the carbs cleaned will help also but you could spend a lot of money doing that and still have a hard time starting it in the cold.

One trick I use to use to keep it idleing when cold was stand there and bump the choke button every time it sounded like it was going to die.

[BillyBoy23]

Hey marine,

It is a 4 stroke motor.

I will try the key thing when I head out tonight. Thanks

Do you think if I sit there with it a while and try pushing the key in it would be able to stabilize after a few mins and should idle fine??

[marine_man]

Yes... once it's warmed up it should idle just fine by itself.

If it doesn't then there's likely some gunk restricting the low speed jet.

marine_man