Motor will not crank or turnover

VThoge

Recruit
Joined
Jul 23, 2010
Messages
3
Boating amateur here. I inherited a 1996 Astro Fish and Ski from my father last year. The motor is a Mercury 2-stroke outboard 115. I took it out on the lake nearby my house several times last year and didn't really have any problems. I had to choke the heck out of it to get it started sometimes, but never was unable to get it started. I thought I would do some maintenance today. I changed out the spark plugs with the correct ones and changed the gear oil today. I thought I would hook up a pair of muffs and a hose and see if it would start after making the changes. It makes a humming noise instead of cranking. I don't know much about the internals of the motor, but I know it should be making more noise than that! I don't really have a good way of testing out my battery, but the motor trimming works fine, up and down, so the battery isn't dead. Any ideas as to how to figure out what's wrong without taking it to a mechanic? Thanks in advance.
 

86 century

Ensign
Joined
Sep 8, 2009
Messages
986
Re: Motor will not crank or turnover

The starters on most outboard haft to spin up pretty fast to get the bendix to rise.

You might have a dead cell in your bat.
Lose or bad conection on a bat cable.

These things are easy to test. Let us know
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Motor will not crank or turnover

Battery dead/weak or y0u have corroded or loose battery connections.
 

aussieflash

Lieutenant Junior Grade
Joined
Feb 5, 2011
Messages
1,004
Re: Motor will not crank or turnover

I don't really have a good way of testing out my battery, but the motor trimming works fine, up and down, so the battery isn't dead. Any ideas as to how to figure out what's wrong without taking it to a mechanic? Thanks in advance.

First thing I bought when I got a boat was a volt/multimeter.It will be your #1 tool.
 

VThoge

Recruit
Joined
Jul 23, 2010
Messages
3
Re: Motor will not crank or turnover

The starters on most outboard haft to spin up pretty fast to get the bendix to rise.

You might have a dead cell in your bat.
Lose or bad conection on a bat cable.

These things are easy to test. Let us know

I hooked up jumper cables to my wife's car and it started to crank and turnover. Still wouldn't start completely but at least it's cranking. I foresee a portable jumper and volt meter in my near future. I'm going to run some fuel stabilizer through it the first time I take it out on the water to clean out everything too. Thanks for the advice guys!
 

Mi duckdown

Commander
Joined
Apr 14, 2007
Messages
2,575
Re: Motor will not crank or turnover

And bring a tow rope. you have not solved the problem.
 

86 century

Ensign
Joined
Sep 8, 2009
Messages
986
Re: Motor will not crank or turnover

By it turning over when you jumped it would say you need a new or better battery.
Pp
You will never find yourself out on the lake saying I wish I had smaller battery.

I have found that larger outboads can be a bit power hungry on start up.


Two years ago I had a battery that would not crank my 200hp merc the same battery is in the motorhome to this day she cranks the 454chevy over no problem
 

VThoge

Recruit
Joined
Jul 23, 2010
Messages
3
Re: Motor will not crank or turnover

By it turning over when you jumped it would say you need a new or better battery.
Pp
You will never find yourself out on the lake saying I wish I had smaller battery.

I have found that larger outboads can be a bit power hungry on start up.


Two years ago I had a battery that would not crank my 200hp merc the same battery is in the motorhome to this day she cranks the 454chevy over no problem

I hear ya. I guess it's time to shop around for a battery.
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Motor will not crank or turnover

At least get it fully charged, then load tested.

While it is out, clean ALL cable ends, shiny bright, and make them tight. Including the short cable between the starter and solenoid.

Even a new battery will not work when the connections are nasty.
 
Top