1993 135hp Mariner Starter Question

[dewman]

I have twin 1993 135 Mariner Outboards. The starboard engine starts fine on 1 battery. The port engine requires the battery switch to be on 'both' to get the starter to fire. Sometimes I have to turn the key 3or 4 times before I will get a response. Seems to be worse after the boat sits for a while (2-3 weeks). When it does fire it sounds like the starter is turning slower than the starboard engine. I am looking for advice on whether the starter needs replacing or is there something else going on.

Thanks

 

[j_martin]

Re: 1993 135hp Mariner Starter Question

I have twin 1993 135 Mariner Outboards. The starboard engine starts fine on 1 battery. The port engine requires the battery switch to be on 'both' to get the starter to fire. Sometimes I have to turn the key 3 or 4 times before I will get a response. Seems to be worse after the boat sits for a while (2-3 weeks). When it does fire it sounds like the starter is turning slower than the starboard engine. I am looking for advice on whether the starter needs replacing or is there something else going on.

Thanks

More than likely the starter needs replacing. If yer handy and know of a starter rebuilder, you can probably put in brushes for about 30 bucks. That's usually what's wrong.

These starters have end face brushes in them, and it is at the bottom of the motor as it's installed on the engine. Conductive brush debris accumulates in the bottom until it shorts things out. Usually the brushes are pretty short by that time anyway.

They can fool you. I once bought a $55 battery for $80 at a marina because I was dead certain that was the problem. Turned out to be the starter.

If you want positive proof, get a magnetic ammeter, one that you hold against a wire that you want to measure the current in, and hold it against any of the heavy wires from the battery to the starter when you're cranking the engine. It should be about 150 amps or so. I'd bet it's over 300. You can compare the two engines.

hope it helps
John

 

[dewman]

Re: 1993 135hp Mariner Starter Question

Thanks. I think when I unwrap it I'll test per your suggestion first. Then we'll see where to go from there.

 

[sschefer]

Re: 1993 135hp Mariner Starter Question

Before you go too far, try hooking that motor to it's own battery without a switch. I had a dual battery switch go bad and it acted just like a failing starter. It was the cheap "Blue Sea" switch. I upgraded to the better one and it's been fine ever since.

 

[j_martin]

Re: 1993 135hp Mariner Starter Question

He's right. A bad switch, or anything that causes a few volts drop will make the starter act funky and draw a lot of current. Yes, low voltage increases current.

hope it helps
john