Brand New Starter Motor Won't Work!

[Arsytee]

Hi, I have a 1982 Yamaha 55hp EL outboard (labelled Mariner but essentially the Jap Yamaha version). The starter motor packed in so I bought a brand new one, wired it up and fitted it last week. I tested the engine on the drive way and all was great, starting like a dream. I got it on the water today and started initially and we cruised for a while. After stopping for some lunch I went to start it again and nothing, not a thing!!!

On getting it back home I have established the following:-

There is power getting to the solenoid and the solenoid is working (you can hear it click when the start button is pressed.
The battery is pumping out just under 13v at the engine block. The earth to the starter is good as is the positive.
If I bypass the solenoid the starter does nothing at all.
I can spin the bendix and its not jammed at all.

What else can I try. Could the starter motor be broken even after a week?

Should I just torch the whole boat and engine?

 

[gm280]

I would remove the starter and take it to an auto parts store and have them test it. I find it interesting that it only worked for a week. Sounds more like a defective starter solenoid or even corroded supply battery wires...both sides. Even if the battery wires look clean and tight, remove them and clean them to shiny metal and retighten them again. Do the same with the starter solenoid wires too. And just because you can hear the starter solenoid clicking, doesn't mean it is passing current to the starter. Contacts inside get burnt and corroded as well and stops the current flow. Make sure you don't neglect the ground wires to the engine casing. So many folks don't even think about that ground and have so many problems and can't figure out why. JMHO!

 

[Arsytee]

Thanks for the reply. Will follow your advice and see how I get on! One day I will get out on the water and NOT have any problems!

 

[frankjohnson]

I think gm280 is dead on, if you still have problems use a volt meter, put ground lead directly to the starter motor housing and the positive lead to the stater power lug have someone hit the start button and see what voltage you have, then move positive lead to cold side of start relay and check voltage when starter is activated, then move to hot side of starter relay and check voltage when starter is activated, then move to battery positive post and check voltage when starter is activated, keep ground lead on starter housing for each test. If voltage at starter lug is low and suddenly jumps up on one of the other test then voltage drop is occuring between the starter and point voltage holds. You can have good voltage untill a load is demanded from it, cocorrosion can build up inside the cable under the cable eyelets and on the outside, moving the cables arround installing your new starter may have broken enough loose for a temporary solid connection. If you show a voltage drop all the way back to the battery then move your positive lead to the positive battery post and ground to the battery ground cable at the battery and check voltage when starter is activated, if voltage good then keep positive lead on the battery and move ground lead to where the cable attaches to the motor and check voltage when starter is activated, this will tell you if the ground lead is the problem. Good luck, electrical connections can make you pull your hair out. Also check the voltage on the wire activating your starter relay it could have a low voltage signal, want to check everything..

 

[Arsytee]

Thanks frankjohnson, I bench tested the motor today using the battery cables from the boat and it worked. Put it back on the motor and go through the solenoid and it doesn't. Tomorrow I will check all the solenoid cables and connections and try again. Thanks for all the tips, very helpful.