Motor wouldn't start.

[gdugas]

My friends motor wouldn't start today after numerous starts and stops during the day. When we checked things out we found the wingnuts not tight on the cranking battery. The battery posts were hot and there was some smoke. We tightened the connections but the motor still wouldn't start. I could hear a small chatter noise coming from the starter when we tried starting the motor. After about a half hour the motor started and we had no more problems. My question is if the battery wingnuts were not tight would this cause the battery to heat up thus causing low voltage until it cooled off. We're scratching our heads here looking for an explantion. Thanks.

 

[Barnacle_Bill]

Re: Motor wouldn't start.

Check all those connections and make sure they are clean. Now take the wing nuts and tie them to a fishing pole for weights. That is all they are good for. Replace them with regular hex nuts. As you found out the wings nuts are notorious for working loose.

 

[Silvertip]

Re: Motor wouldn't start.

Loose connections represent resistance to current flow. Resistance causes heat. Connections at the battery are just one point to consider. The cables have connections on the other end as well so make sure those are clean and tight.

 

[gdugas]

Re: Motor wouldn't start.

Thanks for the replies. We did check all the connections and that's how we found the loose ones. My question was once we had all the connections tight the motor still wouldn't start. A half hour later, it started. Could the battery have been hot causing low voltage until it cooled?

 

[Silvertip]

Re: Motor wouldn't start.

No! But while trying to start the motor you discharged the battery (ran it down) significantly. While you were checking things, it recovered enough to start the engine.

 

[gdugas]

Re: Motor wouldn't start.

We didn't discharge the battery trying to start it. Nothing was happening but a small chatter noise coming from the starter. As soon a that happened is when we checked the connections. Where the wires attached to the battery is where we saw some small arcing and smoke. All things lead to starter being bad but motor has started repeatedly since issue.

 

[Silvertip]

Re: Motor wouldn't start.

If the solenoid is chattering that does not point to a starter problem. It points to an electrical problem -- namely, lack of current flow. The solenoid is activated when the key is turned to START. Since the ignition switch cannot handle all the current the starter draws, it is the job of the solenoid to provide that connection. Prove or disprove a starter problem next time by simply jumping the solenoid (jump the two large terminals). If all connections are clean and tight as you say, there is no corrosion where the cable enters the cable ends, and the battery is fully charged, the starter should spin. If not, it's bad. If it spins normally, the solenoid, the ignition switch, or the connections between them are suspect.

 

[gdugas]

Re: Motor wouldn't start.

Silvertip, We did some major troubleshooting during that half hour when we couldn't get the motor started. My friend contacted the guy that put the motor on the boat(he is a friend of ours who is a boat motor guru)and he had us going through a bunch of tests, one of them was what you said but all we got was arcing and nothing else. I was sitting there thinking to myself the whole time that it looked like a dead battery and even suggested we try the trolling motor battery but they were convinced it was the starter. We were getting ready to rope pull it(Merc 200, yikes!) when I hit the ignition and the motor rolled over. After that no more problems. Here is a reply I got from an RV forum. See what you think. Thanks.

The high resistant connection atthe battery post prevented the battery from being charged, several starts depleted the charge in the battery, thus the chattering, after a few minutes the chemical charge started the engine which now can recharge the battery.

Batteries heat due to a high rate of electron transfer into or out of the battery. both a high rate of charge and a high rate of discharge will heat a battery.

 

[Chris1956]

Re: Motor wouldn't start.

Silvertip is correct on his diagnosis, from the description you gave. Resistance and current flow both cause heat. Starters are rarely intermittent, unless they have a shorted winding, which you will ususally hear while cranking the motor.

I also think your battery recovered a bit, while you were troubleshooting. You now need to run a charging test to see if you ruined the charging system regulator or rectifier.

 

[gdugas]

Re: Motor wouldn't start.

Thanks. Will check out. When we we did start the motor, it didn't sound like the battery was not fully charged. It spun over normal.

 

[Fl_Richard]

Re: Motor wouldn't start.

How did you tighten the wing nuts? It's possible ---- After the arcing there was carbon deposits that were preventing a good solid connection. You hand tightened the wing-nuts compressing the metal over the carbon. The bolt and stud were hot and as they cooled they expanded causing what was an intermittent connection to tighten up. Then the motor started.

Like I said, it's possible. - Anything is possible.