starter spins backwards, help!

[FisherOfCods]

I have a 1997 Evinrude 115 with a starter problem from hell. I rebuilt the old starter, put it back on, and it spun backwards. Replaced the solenoid, still spinning backwards. Bought a new starter, and yes, it spins backwards too. I even tried hooking the starters (old and new) directly to a 12 volt battery, and they still spin backwards. It needs to spin clockwise to engage, but they both spin counter clockwise. None of the other posts on here were relative to my issue. What am I doing wrong? Please help!!!!

 

[boat1010]

Re: starter spins backwards, help!

Are you sure you have the neg. and pos. reversed? The solenoid just engages the starter. Nothing to do with the rotation.

 

[CR CRUISER]

Re: starter spins backwards, help!

When viewed from the top which was does the starter spin?

Correct me if I'm wrong but shouldn't the starter spin CCW (when viewed from the top) in order to turn the flywheel clockwise?

 

[Fl_Richard]

Re: starter spins backwards, help!

Your looking at the Bendix. Brute centrifugal force sends the Bendix up the shaft. It looks like it's running backwards but it's probably fine. Especially if the old one is turning the same direction.

If the Bendix is not going up and engaging the flywheel then you need to check your battery cables or apply a very small amount of machine oil to the Bendix shaft so it does not bind.

 

[Silvertip]

Re: starter spins backwards, help!

As mentioned, look down on the flywheel and starter - in order to turn the engine clockwise the starter needs to spin counter clockwise. If the bendix is not rising to engage the flywheel, you have either a weak battery or a bad bendix. Grooves in the starter shaft match ridges inside the bendix. When the starter is activated, initial rotation of the shaft drives the bendix upward in sort of a screw fashion.

 

[Texasmark]

Re: starter spins backwards, help!

Your starter is a DC motor. DC motors are polarity sensitive. If your motor frame is grounded to the engine block (which it is) and the neg terminal from your battery is also connected to the engine block, your starter is NOT turning backwards. The only way that can happen is to have the battery pos terminal connected to the block rather than the neg.

So do as the guys suggest. While you are in there, you might remove, clean, and reinstall your high current connections, between the battery and the engine block on the neg side, and between the starter hot terminal, solenoid, and wiring to the pos battery terminal...."clean, bright, and tight".

Mark

 

[JB]

Re: starter spins backwards, help!

Sorry, guys. You cannot get a series wound DC motor to run "backwards" by reversing the polarity. Starter motors are all series wound and are not polarity sensitive.

But you can get it to run "backwards" by connecting the brushes backwards, reversing the polarity of the armature (rotor) relative to the field. An inexperienced wrench "rebuilding" one might do that by accident.

I don't think yours is running "backwards". I think you need to clean up you wiring and connections, as suggested a couple of times above.

 

[Texasmark]

Re: starter spins backwards, help!

Sorry, guys. You cannot get a series wound DC motor to run "backwards" by reversing the polarity. Starter motors are all series wound and are not polarity sensitive.

But you can get it to run "backwards" by connecting the brushes backwards, reversing the polarity of the armature (rotor) relative to the field. An inexperienced wrench "rebuilding" one might do that by accident.

I don't think yours is running "backwards". I think you need to clean up you wiring and connections, as suggested a couple of times above.

Hmmmmm. Gotta get the Motors and Generators book out tomorrow and refresh my memory it looks like. I do however vaguely remember flashing the Field winding on dc generators with mechanical regulators to insure the polarity was correct as your wrench "rebuilding" comment implies.

Mark

 

[jimg984]

Re: starter spins backwards, help!

JB is correct, north pole and south pole is reversed by changing the feed to them... i build a wench doing this with a set of soloinds, which would switch the feeds.... it run either direction as i wanted Ford automive starter

 

[Texasmark]

Re: starter spins backwards, help!

Hmmmmm. Gotta get the Motors and Generators book out tomorrow and refresh my memory it looks like. I do however vaguely remember flashing the Field winding on dc generators with mechanical regulators to insure the polarity was correct as your wrench "rebuilding" comment implies.

Mark

Well I boned up on my motor theory this morning and I told a big fat lie yesterday.

As the master (MR. JB) stated, correcting me, you can't change the direction of any series, (shunt, or compound motor....per my references) by reversing the power leads . So, Mr. Fisher of Cods, since you said you purchased a new starter and one would sincerely doubt that you would go into it to change the wiring, neither of your starter motors apparently is running backwards, regardless of how your battery is connected to your engine..............
-------------------------
Confusion......well, how about my trim motor that I can reverse by just reversing the polarity of power applied.........DA DA Enter the PM motor: But you can on PM (permanent magnet) motors where either the armature or stator are permanent magnets (no wiring required with fixed N-S poles) and changing the power leads only changes the non magnetic (electrical) circuit which is the requirement (change the polarity between the armature and field circuits) and WILL (as he said) change the direction.

Now that makes perfect sense and solves my misunderstanding in the first place.

So apparently my trim motor is a PM type and that is what I had in mind when I shot my mouth off yesterday. Funny, this is the deepest I have dug into motor theory in a very long time and never this far on starters, and I have been around this stuff all my life. Like I keep saying, learn something new every day.

So, I got that settled and we all got a little lift out of the exercise.

My apologies to the forum.

Mark

 

[FisherOfCods]

Re: starter spins backwards, help!

Okay, I stand corrected, the starter spins the correct direction to spin the flywheel (counter-clockwise), but it must spin clockwise to be engaged on both the old and new starters. I have 2 brand new batteries, all connections are clean. I'm about ready to turn this thing into a paddle boat!!! haha! I do appreciate all of your help guys! If the solenoid is responsible for engaging the starter, could the brand new solenoid be bad?

 

[Silvertip]

Re: starter spins backwards, help!

On one hand you agree that the starter must spin CCW to make the engine turn clockwise, but then you contradict yourself by saying both the old and new starter must turn clockwise to engage the flywheel. Are you turning the bendix up the shaft by hand to determine this by any chance? If so, you are mechanically challenged and that proves the point. The motor drives the bendix up so it MUST turn CCW to do that.

 

[JB]

Re: starter spins backwards, help!

"all connections are clean".

Did you, personally, remove and clean all connections? Looking okay and being tight is not good enough. That includes the electrical connection between the starter motor and the engine block.

Worst offender is the battery negative (ground) cable connection to the engine block. Takes less than 5 minutes to undo, scrub bright and reconnect. . . .cost zero bux.

This is by far the hardest thing to convince folks who do not speak fluent Ohm's Law. Thousands of starters and solenoids that are just fine get replaced and the dang things still won't start.

Sorry if I am preaching to the choir, but this is too simple and too important to forget.

 

[bruceb58]

Re: starter spins backwards, help!

:redface:

Sorry, guys. You cannot get a series wound DC motor to run "backwards" by reversing the polarity. Starter motors are all series wound and are not polarity sensitive.

Hmmm...learned something new today. Did not know that was a characteristic of series wound motors.

I believe most of the newer GM gear reduction starters are all permanent magnet type so this would not apply with those.

 

[JB]

Re: starter spins backwards, help!

Right. I don't think it would apply to any PM motor.

 

[Texasmark]

Re: starter spins backwards, help!

:redface:Hmmm...learned something new today. Did not know that was a characteristic of series wound motors.

I believe most of the newer GM gear reduction starters are all permanent magnet type so this would not apply with those.

Bruce,

Somehow I knew you would get tuned into this. He said series wired starters. After researching half a dozen sources of info today, half tech manuals....Motor, Chilton, Ford tractors 55-60, Ford tractors 65 up, Merc service manual, ABC's of Motors and Generators, several www sites responding to the querry: How to determine the direction of rotation of a dc motor, it became obvious that what he said is how it happens and how it gets done, unless as I said you have a PM motor.

The series dc motor is what's used in GM's Diesel-Electric electromotives that run the rails. The diesel engines charge the batteries and the batteries supply dc power to series dc motors which is exactly what you need when you are trying to get 100 20 ton cars of coal running from Colorado to Houston, TX. If you will do your homework, you will easily see this is the same reason starter motors are series wound. But they are not just series wound. There are 2 circuits, 4 brushes, so essentially they are series-parallel (as my references point out), but they are in series enough to provide the series wired benefits: High torque, lack of rpm control, runaway at light-no load conditions, and all that stuff you don't find in a starter unless you have it in a vise on the work bench.

So, Bruce, reading between the lines, are you implying that new GM starters can be operated forward and backwards............Geez I'm glad I divorced myself from that "brand" years ago and bought a quality Mopar product.

Geez, maybe my son needs to get a job and get off my ................

Mark

 

[Texasmark]

Re: starter spins backwards, help!

You know we have to hang in there with questions like this. We all focus upon what's important to us and until we have a problem with something, we don't fully concentrate on it. Maybe you do, but I don't. I have other things to occupy my time......Rocky Mountains ring any bells........ How many times have I admitted to that.

So, lets stay with Mr. Fisher of Cods and get his problem solved.

What else can I do?

Mark

 

[Lyle29464]

Re: starter spins backwards, help!

my guess is bad wires or batteries topped off with confusion.
run a set of jumpers from a car to your engine block and battery side of start solenoid.

 

[smokeonthewater]

Re: starter spins backwards, help!

I have never personally seen a series wound starter motor.....
I have however seen both grounded cases and floating grounds on starters.... if he had a floating ground he could have it wired wrong.....

if the battery cables are reversed and he has supplied positive to tthe ground of the engine then he may have more gremlins to chase down

For a real easy way to demonstrate rotation turn the bendix by hand.... whichever way it turns to move up is the OPPOSITE of the direction that the starter must turn....

 

[Silvertip]

Re: starter spins backwards, help!

Fisherofcods -- where are you? But then with all the theories his head is probably spinning (in the wrong direction).