slow turning

theboyner

Cadet
Joined
Apr 7, 2012
Messages
16
Hello are you out there. I have a 1988 Mercruiser 3.7 L. It has been laying up all winter, started and run for a while only once. Trying to get it underway for the season and cant get it to start. It seems to turn over very slowly and drain down battery power quite quickly. Have checked batteries and in fact just installed a new one in case i had battery problems...no change. ? Is slow turning normal for this old engine. The batteries , in series setup, have been moved to the Cuddy by previous owner and it's a long way to push power, i realize. Comments please .Thanks Boyne
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: slow turning

Is slow turning normal for this old engine.

No, with less compression and more wear they tend to turn easier.


Long distances of battery cables require larger wire, and CLEAN, TIGHT, connections of both positive and negative battery cables, and both ends of each cable.
 

wellcraft-classic210

Master Chief Petty Officer
Joined
Sep 22, 2010
Messages
839
Re: slow turning

Lots of possibilities --

Hoping you mean in parrallel not series for the batteries. Very important as parrallel is + to + and - to - and will provide 12 volts-- while Series wiring + to- / + to - will deliver 24 volts and could damage components.

Is everything else off that draws a lot of power

Check all connections battery to starter for corrosion and tightness.

Try a known good battery with short known good cables.

Does your engine turn freely -- Pull the plugs & turn the crankshaft by hand to ensure that.
 
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