Solenoid?

So when testing my engine, there was a couple of times when the starter did not kick off. We had to unhook the battery to stop it. My dad thinks it's the solenoid mounted to the engine. Any thoughts? Would this one be a good replacement?

http://www.go2marine.com/product.do?no=93957F

Seems like whatever is on there now is a standard automotive solenoid.

Thanks!

Once they stick the contacts arc to each other internally and cause a rough spot from prolonged contact and high amps from the battery. It will continue to do this so go ahead and replace it,this will keep you from continously turning over the starter until you can get the engine cover up and tap on it to make it release. Or the boat will start and want to keep the starter engaged and destroy the bendix on the starter and damage the flywheel as well. this is common . It's a PITA to get everyone out of the way to open the engine cover and puts undue strain on the starter as well. You may look at how old positive battery cable is as well . If it has lots of corrosion and is burned up at the positive connection at battery post. Low voltage to solonoid can make this a reoccuring problem. been ther done that

I'll test the voltage at the solenoid. The battery cables are brand new 1g marine grade. The battery is new as well so none of those.

Have y'all been replacing with standard automotive solenoid or a marine grade?

replace with which ever one is on there now, that is if it works and starts good.

GottaSki wrote: Starting (good) or Deep Cycle (bad).

Here's a stupid question: why is a deep cycle bad?

To add,
a deep cycle battery has higher internal resistace. Just a few tenths of ohms doesn't matter till you pull 100+ amps and the V-IR and you loose 4-6V at the battery.
The starter is a DC motor, and pulls more amps the slower it goes, so you then have a runaway train of heat and wasted energy and smoked cables, starter and solenoid.


When a starter stalls its like a dead short, and pull major amps, but those big amps pull the voltage down further on a DeepC battery due to its internal resistance.

Less applied voltahge means less work done my the motor and more waste heat on all components

The lower available voltage also has less clamping force on the solenoid contacts, which then gets resistive, heats up, and welds its contacts together from the arcing across the contacts.

David,
Here is a good explanation on marine batteries:

Marine Batteries

What Peter says is true for a deep cycle conventional battery. They are built for constant draining and charging. If you do that with a start battery, their life will be shortened. Can be used in an emergency though. The same with using a start battery as a deep cell. That will shorten the life as well.

Optima doesn't have plates per say. They use what they call their proprietary Spiral Cell technology. That's why the batteries look like there are 6 jar type batteries in the case. They don't say why their batteries are dual purpose, but I have an email into them for some technical explanations. Here is the site for the Optima D31 tech sheet. It boasts a 900 CCA:


Optima D31M Data

I will not try to convince anyone to buy an Optima if they feel they can't be used as a cranking battery. Optima says the dual purpose batteries are designed for this and I have been convinced it's true as I haven't had one fail on me YET. Knock on wood.

I would check for the other problems I mentioned before buying a new battery though. Also you might take your starter out and have it diagnosed if my other suggestions don't pan out.
Kurt

88 Nautique wrote: Low voltage on the "start" terminal on the solenoid, (from your ignition/start switch) will cause this problem. My new solenoid did the same thing so I checked the voltage on the start terminal at the solenoid with the starter disconnected from the solenoid and the key switch in the start position. (Note: don't hold the key in the start position for a long time. The solenoid is a momentary relay and will burn the coil open if left on a long time.) Should be close to 12V. If you're getting a reading of 9 volts or less, check your circuit path for a corroded or bad connection. You can usually clear the stuck solenoid by tapping on it after disconnecting the battery. What I found on mine was from a corroded termination from the engine wire harness at the breaker on the dash. Low voltage will not "slam" the contacts together. The electromagnet will slowly engage causing the contacts to arc and weld together, causing your starter to run on. Kurt

this is the path I'd take.......... been here several times, old boats , old wire = low voltage