johnson 1973 25 hp elec start

stratosjoe

Cadet
Joined
Mar 16, 2010
Messages
7
With a freshly charged battery my always faithful motor turns over two slow times and starts fine ,runs fine . is there a keyway under the flywheel that could be partially bent causing it to act like a little out of time
 

kbait

Commander
Joined
Nov 13, 2007
Messages
2,471
Use battery cables to jump the starter motor directly from good battery. If it's still slow to turn the motor, you likely need a starter rebuild/replace.. If it's running fine otherwise, not likely to be flywheel key.

Good luck!
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
A 1973 motor certainly has had time to wear out a starter, but it is pretty unlikely since those motors crank so easily. If it is cranking slowly, the most likely reason would be high resistance in the starting circuit (cables). Take them off and scrape/wire brush everything shiny bright. And of course make sure the cables aren't corroded half way through or something like that.

EDIT: And make sure that "fully charged" battery doesn't have a dead cell or something. Have it load tested. Many or most battery stores will do that for free.
 
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