Yamaha 115 hp starter only spins

[robert graham]

Makes me wonder what percentage of folks really understand how this works?....or even think about it...or even care?....But for myself I love knowing how and why things work!....I've been running that little bendix up and down with my fingertip for 25 plus years and never got how it worked....maybe the brain a little slow?

[cpostis]

Voltage Drop Test for Starting Circuit-FYI

Outboard Ignition Troubleshooting - Page 36

Voltage Drop Measurement

Start by using a good digital auto-ranging volt meter capable of reading 1/10th of a volt. The use of an auto-ranging meter will allow for more accurate testing without damaging the meter due to an incorrect range setting.

Remove the spark plug wires form the spark plugs and connect them to a spark gap tester and remove the emergency stop clip as well. This prevents the engine from starting and also reduces the chance for you to get shocked by the ignition system.

Before testing, remove and clean all battery cables and connection points.
Testing the Positive Battery Cable to the Engine

Select the DV Volts position on the meter.
Connect the Red (Positive) lead of the meter to the positive battery POST.
Connect the Black (Negative) lead of the meter to the starter solenoid terminal where the positive battery cable is connected.
Using a remote start switch, activate the starter solenoid to spin the engine and observe the reading on the meter. A reading above 0.6V is an indicator of a bad cable or bad connection.
(A) If the meter reads above 0.6V, move the Black lead of the meter to the positive battery cable terminal on the starter solenoid and retest. If the reading drops to below 0.6V, the cable connection is bad.
(B) If the meter still reads above 0.6V, move the Black lead of the meter to the positive battery cable terminal on the battery and retest. If the reading drops to below 0.6V, the cable is bad or undersized.

Service Note: A bad power connection to the ignition or battery charging system can be found by connecting the Black lead of the meter to the power connection of the ignition system or charging system and working your way back to the battery positive post. At no time should you see a reading above 1V.
Testing the Negative Battery Cable to the Engine

Select the DV Volts position on the meter.
Connect the Black (Negative) lead of the meter to the negative battery POST.
Connect the Red (Positive) lead of the meter to the engine block where the negative battery cable is connected.
Using a remote start switch, activate the starter solenoid to spin the engine and observe the reading on the meter. A reading above 0.6V is an indicator of a bad cable or bad connection.
(A) If the meter reads above 0.6V, move the Red lead of the meter to the negative battery cable terminal on the engine block and retest. If the reading drops to below 0.6V, the cable connection is bad.
(B) If the meter still reads above 0.6V, move the Red lead of the meter to the negative battery cable terminal on the battery and retest. If the reading drops to below 0.6V, the cable is bad or undersized.

[99yam40]

Great explanation!...so that metal piece at the base of the helix gear is a Weight that provides inertia(body at rest)....I'll admit to not ever really understanding how that thing worked!....a lightbulb over the head moment for me!....leave it to Rodbolt to clarify how stuff works!

It does add some mass, but there is a clutch type of thing inside it.
if you get too much oil/lubricant down in it it will slip instead of turning the flywheel. Ask me how I know this
good thing is you can clean it

[rodbolt17]

it is called an over running clutch.
some call it a friction drive.
but either way NEVER spray it with any fluids.

[pstephens46]

Hmm think were a couple suggestion on spraying lube on bendix, wonder if the OP did this and now made situation worse?

[rodbolt17]

I read it on the internet.
must be correct technical information.

if ya don't belive me hose it down with wd-40 or something and see what happens.

PS rubbing alchohol will cure the issue you just created.

[cpostis]

On the internet it says, pour molasses over the gear and shaft. Sweet, huh?

Have you done the voltage drop test? You can also use jumper cables hooked up to a know good and charged battery (negative to starter body, positive to positive post). Be sure to remove your kill switch clip. If the gear engages, you know it's not your starter and the problem is elsewhere.

[rodbolt17]

in the amount of time it takes to figure out the issue is elsewhere with jumper cables I can tell where the issue is with a multimeter.

Yamaha starter failure is incredibly rare.
we may have sold 3 in the past 5 yrs and they were due to the boat sank and no one disassembled the starter PRIOR to applying power.

bad connections, failed cables. not so rare at all.

did one Friday before last.
man backed it up at exactly 4:30 PM.
by 4:40 it was fixed and running.
loose ground cable at the block.

you could actually see the arc marks when I disassembled it for cleaning.

when I hit the trim with one lead on the negative battery terminal and the other on a good block ground it read 9v and nothing happened.

instantly told me I have a cable/connection issue.

[Taylodp1]

Well this morning I ran a wire (pretty much the same gauge as is normally used from the battery to the starter) from the positive battery terminal to the output side of the starter relay. As soon as I touched the battery terminal the starter began to spin but still the bendix did not spin up high enough to engage the flywheel. I have not run a volt test as is mentioned in some of the posts. I'll have to wait on a friend to help with that. However, I did notice that when all is hooked up normally and I turn the key to start the motor the volt meter on the dash goes down below 10 (10 is the lowest reading on the gauge) and then will slowly come up above 10 but will not get as high as the 12.5 or so when I just turn the key to ON and do not attempt to turn the key to start it. Is this an indication of anything?

[pstephens46]

Looks like voltage drop to me. Had a sim situation and it was a poor connection.

[pstephens46]

Trim Tilt work normally? Just curious....

[Taylodp1]

Yes it does.

[boscoe99]

Makes me wonder what percentage of folks really understand how this works?....or even think about it...or even care?....But for myself I love knowing how and why things work!....I've been running that little bendix up and down with my fingertip for 25 plus years and never got how it worked....maybe the brain a little slow?

Me too. Thanks to Google it is a whole lot easier today than it used to be. Just need to be careful cause there is so much misinformation out there as well.

I particularly like animations of what does what and when.

Anyhoo, here is what I believe to be a pretty good article.

How the starting system works | How a Car Works

https://www.youtube.com/watch?v=8WD5Q_PF3pM

[Taylodp1]

In response to CPOSTIS I got another battery and hooked the negative jumper cable to the starter body and touched the positive cable to the positive lead on the starter and the bendix did engage the flywheel so I feel sure the new starter Is ok.

[boscoe99]

Rodnut (Jesus) 'splainin how a starter motor an solenoid work.

https://www.youtube.com/watch?v=9PWG6Il_ZJI