engine cranking slow and battery terminals smoking

[Nrizzo20]

Hey everyone,

Long story short as ive posted a few times in the past couple months. I had a 1993 4.3 mercruiser. My motor blew so I bought a used one. I replaced it with a 1989 4.3. Everything matched up, wiring harness and all. It was completely cold when I showed up. I started it a few times with no issues, cranked perfectly and ran awesome. Only part I had to replace was the starter slave solenoid (he had it bypassed). I took the solenoid off of my old engine that I never had any problems with and hooked it up.

Last night after I installed the engine I went to start it and got smoke coming from the battery terminals (extremely hot and nearly glowing red on the ground) and it was cranking over slowly. The battery was completely charged and I did test it. So I cleaned all my terminals and the ground from the engine block to the battery. Starter wasnt hot at any time nor were any of the wires to the starter. I tried started the boat again 3 or 4 times and the cables did not heat up the first couple times but it was still cranking over slowly. I checked all other connections again for heat without taking anything off and tried again. But once again I got smoke and heat on both positive and negative terminals on the battery... the boat wont start of course and im at a loss. any help would be appreciated. thank you!!!

 

[Bondo]

and got smoke coming from the battery terminals (extremely hot and nearly glowing red on the ground) and it was cranking over slowly.

Ayuh,.... The terminals gettin' Hot, says they ain't clean enough yet,.....

Pull the starter, 'n bench test it, or use the one off the old motor,.....

 

[gm280]

Also check the starter solenoid and verify it is flowing the current to the starter properly. If it is defective, it could be the problem. You can easily test that by jumping from the positive terminal on the battery straight to the starter and see if it spins properly. If so, buy a new starter solenoid. JMHO!

 

[poconojoe]

Could you have the wires crossed somewhere? A dead short from positive to negative when you turn the key? Negative wires can be colored yellow sometimes.

 

[tpenfield]

Yea, check to see if the solenoid is getting hot. Sounds like current is going elsewhere.

Battery might be toast at this point though.

 

[Nrizzo20]

Also check the starter solenoid and verify it is flowing the current to the starter properly. If it is defective, it could be the problem. You can easily test that by jumping from the positive terminal on the battery straight to the starter and see if it spins properly. If so, buy a new starter solenoid. JMHO!

Should I run a jumper cable from my car straight to the starter and see if it turns over normally?

Ayuh,.... The terminals gettin' Hot, says they ain't clean enough yet,.....

Pull the starter, 'n bench test it, or use the one off the old motor,.....

Thanks bondo, that was going to be my next step. I will swap them out tonight after work and give you an update

 

[Nrizzo20]

Update: replaced my starter and that problem is now fixed. Cranks over perfect and no wires are hot. But, the engine won't start now. I am getting spark and fuel to the carb. I even tried a little bit of carb fluid and still no luck. I'm debating maybe just setting the the thing on fire...

 

[tpenfield]

Update: replaced my starter and that problem is now fixed. Cranks over perfect and no wires are hot. But, the engine won't start now. I am getting spark and fuel to the carb. I even tried a little bit of carb fluid and still no luck. I'm debating maybe just setting the the thing on fire...

The old starter might have helped in that regard