[ecko5233]

i got a 81 merc 40 hp one of 3 grounds r smoking wan i try to start it and the tarmamals turn red the - and + ? i'm lost a got the book four it but no help

[Sig_Mech]

Your ground connections are bad. I would venture to say that thet are either loose, corroded or a combination of the two. Please do not try stsrting your motor until you get this fixed. Disconnect all the affected cables from their respective connections and check their condition. If the cable ends look good then clean them up with a wire brush or some sand paper, reconnect them and make sure they are tight. If the cable ends look damaged either by heavy corrosion, burnt/split insulation or frayed wires, then the cable ends will need to be replaced. Before replacing the cable ends, I would check the entire length of the cable/wiring for other damage. If they turned red there is a possibility of melted/missing insulation elsewhere on the cable.
This should go without saying but make sure you have the positive (red) cable on the positive battery terminal and the negative (black) cable on the negative battery terminal.



------------------------------------------------------------------------------
A "shortcut" usually isn't.

[Jbell]

I'm no expert, but the same thing happened to me just two days ago. I used steel wool to clean my terminals and changed the corroded cable connector and the engine fired right up without the smoke. I have a 1980 Merc 90 hp.

[ecko5233]

ok but wan i pull the plugs out it turns good and no smoke but wan i put it back in same thing turns hard and smoke

[Scaaty]

they are either loose, corroded or a combination of the two

We need to tell ya twice??

[Sig_Mech]

Ecko, when you pull the plugs out there is no load (compression) that the starter has to fight against. The harder the starter has to work, the more amperage it needs to draw from the battery. The higher the amperage, the more heat it creates in the battery cables. The more heat, the more smoke.........kind of a vicious circle here isn't it? Any corrosion, loose connections or bad terminations will cause more resistance in the cables and increase the current draw. See where this is going?




-------------------------------------------------------------------------------
A "shortcut" usually isn't.