1991 Force 70hp motor not starting....is my diagnosis correct?

[Cannondale]

OK, bought a 1991 Force 70hp motor a few weeks ago to repower my 16' Quantum bass boat. It ran well initially, but yesterday the starter began turning very slowly and then not at all....only a click when turning the key.

So, lacking a volt/multimeter right now, I began a "poor man's" diagnosis of the problem. Did check all fuses before beginning anything and all are good.

So, first, due to the starter motor turning slowly, I thought the starting battery was a bit low on charge due to it sitting for a few weeks in the cold, so I threw a charge on it. According to the charger, it was a bit low but not bad. Anyway, the charging of the battery didn't make a difference...still only getting a click when turning the key, no starter motor activity at all.

Next, I jumped the neutral lockout switch wires, essentially removing it from the starting circuit, but that didn't make a difference....still no starter motor activity.

Then, I fed 12V directly to the starter motor from the battery via a jumper cable. Starter motor turned over as soon as the voltage was supplied.

So, this leaves me one option....the starter solenoid. It's the only thing in the starting circuit left, right? Cannot think of anything else in the starting circuit I missed. The stator, rectifier, etc. are all in the ignition side of things and wouldn't prevent the starter from simply turning, right?

Any other thoughts before I order a new starter solenoid?

Thanks.

 

[pnwboat]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

Before you change the solenoid, double check all of the battery cable connections both at the battery and the negative cable at the engine block. Undo the connections and clean them with a wire brush or similar tool to get them good and shiny. Bad battery connections is a common cause for the symptoms that you are experiencing. Cleaning also doesn't cost you anything.

 

[Cannondale]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

Before you change the solenoid, double check all of the battery cable connections both at the battery and the negative cable at the engine block. Undo the connections and clean them with a wire brush or similar tool to get them good and shiny. Bad battery connections is a common cause for the symptoms that you are experiencing. Cleaning also doesn't cost you anything.

That was one of the first things I did, although didn't mention it. Did that when I first mounted the engine two weeks ago. Would have been senseless to not clean all the connectors when I had them loose.

 

[pnwboat]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

I would agree with your diagnosis and suspect the starter solenoid itself is bad. If you had a cheap multi-meter, you could measure the voltage drop across the solenoid to confirm that it's bad. Starter solenoid runs around $40. Extremely unlikely that a bad stator or rectifier would cause your problem. Same thing with the ignition system. Not a likely cause.

A bad battery could cause a problem, but you mentioned you used jumper cables from the battery and it was OK. I assumed that this is the same battery that you've been using all along, so that eliminates the battery.

One other thought....bad battery cable. Need an ohm meter to verify.

 

[roscoe]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

One other possibility.
The boat and motor just recently met, and it appeared to be love at first site, but all relationships have their ups and downs.

My guess is that the boat said something like "Is that all you got?", and
that upset her(the motor), and she just needs time to get over it.

 

[Cannondale]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

One other possibility.
The boat and motor just recently met, and it appeared to be love at first site, but all relationships have their ups and downs.

My guess is that the boat said something like "Is that all you got?", and
that upset her(the motor), and she just needs time to get over it.

Got to be one of the best replies to any post I've ever read.

But....how to get the motor over this spate of being upset? I treated her to full synthetic Mercury 2-stroke oil and lower unit lube, not to mention the new NGK plugs....I'd have thought all that would have put her in a better mood, but I see I was wrong. What now?

 

[roscoe]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

You should buy her some bling, like a solenoid.
But ultimately, the boat will need to apologize.
Perhaps the boat could buy her a new steering cable, so they could work more smoothly together?
Happy Boating.

 

[JB]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

at roscoe.

 

[jason32038]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

Check the jumper wire and connections from the starter to the solenoid and make sure the main ground is clean and tight on the block. Reason...clicking noise means solenoid SHOULD be functioning properly. Maybe even check starter magnets.

 

[Cannondale]

Re: 1991 Force 70hp motor not starting....is my diagnosis correct?

Well, as an update, I took the starter apart.....and the brushes were in horrible shape. All sorts of carbon pieces fell out when I removed the end cap and the brushes look burnt....badly.

Guess this is where my problem is really located.

Have a new starter on order and arriving this week. But also ordered a solenoid too as the one on the motor was not really the "proper" solenoid.......rather have the correct part than one that just works.