1986 merc starting issues

[Dsundby]

I have a 1986 merc 115hp engine. I've been experiencing some starter issues lately. Now when I turn it over it just clicks. So I put the battery charger on the battery, and tried to jump it. However, when I jumped it it didn't even turn over. I checked the voltage of the battery and it reads 0.5 volts after jumping it. When I removed the battery cables, they sparked when I removed them. I removed the starter solenoid wire from the starter and put it back on and tightened it down. Then the sparking stopped from the battery. I have no clue what's going on.

 

[Pusher]

Have you tried connecting to your vehicle battery and bypassing the boat battery altogether? The clicking means you have enough juice to plunge the magnet in the solenoid and potentially connect the starter to the battery. If it's one solid click then you should be connecting. If it's a chattering click then your battery might be too weak to keep the solenoid engaged.

I would connect your boat leads straight to your vehicle battery and see if there's any difference.

Someone else will know better than me, just thought I'd keep the ball rolling.

 

[Dsundby]

I was gonna try that. I'm just not sure why it wouldn't start when jumped. The battery just goes dead.