Slow crank 74 evinrude 3 cyl.......frustrated!

Ozark74

Recruit
Joined
May 21, 2011
Messages
4
Long time reader, first time poster.

I have a 1974 evinrude 70hp 3 cyl. that was willed to me. My son and I have been trying to raise it from the dead as a project. We've rebuilt carbs, replaced impeller, new plugs & wires, new fuel lines & tank. We've tried to start motor and we get a slow crank as if it's dead battery or bad starter. I had starter tested (they said didn't have enough torque to spin motor fast enough). We replaced starter and still have slow crank. I even bypassed wiring by putting jumper cables directly on starter and grounding on block. the motor spins freely with plugs removed.

At this point Im looking for any advice.

Chris
 

wifisher

Chief Petty Officer
Joined
Mar 9, 2011
Messages
578
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

The only thing that I see that you missed is the battery condition. How old is it? Have you load tested it?
 
D

DJ

Guest
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

1. Disconnect the battery.

2. Remove the negative battery terminal form the engine block and clean thoroughly.

3. Reconnect and reconnect battery.
 

Ozark74

Recruit
Joined
May 21, 2011
Messages
4
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

In testing the motor I was actually using jumper cables from my car battery. I hooked them directly to boat positive and negative leads on boat. When that didn't work I bypassed leads on boat tand grounded to the block and. Positive right on starter lead. Same problem exists. Would an active car battery in your daily driver not be strong enough to crank my evinrude?
 

wifisher

Chief Petty Officer
Joined
Mar 9, 2011
Messages
578
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

Your car battery is plenty strong to crank the boat motor, but you jumper cables may not have been capable of carrying enough current. There could have been a bad connection on either end, or a bad cable.

Remove and clean all battery cable connections, and load test your battery.
 
D

DJ

Guest
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

In testing the motor I was actually using jumper cables from my car battery. I hooked them directly to boat positive and negative leads on boat. When that didn't work I bypassed leads on boat tand grounded to the block and. Positive right on starter lead. Same problem exists. Would an active car battery in your daily driver not be strong enough to crank my evinrude?

It should, that still may not be allowing a good connection.
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

Jumper cables are absolutely not enough. You need a solid, clean bolted connection with a heavy-gauge electical cable, for both 12V and ground.

Not sure why OMC starting systems are different from a typical automobile starting system, that way. But I've seen it again & again. Have picked up at least two good motors, cheap, because seller thought compression was low, when all it was was slow cranking due to poor connections. Seen people buy new starters & solenoids ($200), then give up on the motor in frustration, when all it was was poor connections.
 

Fed

Commander
Joined
Apr 1, 2010
Messages
2,457
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

2 minutes with a voltmeter and someone to turn the key would answer all your questions.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,112
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

Examine your cables and wires. Corrosion inside the casing is not uncommon. When you get corrosion it robs you of voltage.

Every wire and cable needs to be inspected. Every connection needs to be removed, sanded off with sand paper and re-installed tight...... this includes the starter mounting tabs.
 

Ozark74

Recruit
Joined
May 21, 2011
Messages
4
Re: Slow crank 74 evinrude 3 cyl.......frustrated!

Thanks guys . put new cables and battery in it and it fixed the problem. Now motor cranks normal, but doesn't even come close to starting. Checked fuel and we are good there. However, tested spark at plugs (no spark at all three cyl.). Any suggestions as to what to check first?
 
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