1972 Evinrude/Johnson won't start

Barnacle1970

Recruit
Joined
Jun 30, 2015
Messages
3
I have a 1972 evinrude 25hp 2 stroke that has recently had some trouble starting. We inherited the boat several weeks ago and found that it would only run at or slightly above idle. We adjusted the timing and it fixed the issue. The boat ran great for the next 3 or 4 trips to the lake until last time. The motor started sputtering and bogging down until it eventually quit, and wouldn't start, leaving us stranded in the middle of the lake. I left it in the garage and the next morning discovered a thick black oily goop had dripped out of the exhaust overnight. I cleaned out the carb and fuel filter with no success. If you crank it enough you can get it to sputter a little bit but it won't idle and will die after a few seconds. Does anyone have any ideas/suggestions? Could it be that we adjusted the timing wrong and gunk has been building up in the motor until it was thick enough to inhibit running? Thanks!
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Check your compression and then your spark which should jump a 7/16 " open air gap.
 

Barnacle1970

Recruit
Joined
Jun 30, 2015
Messages
3
I don't have a compression gauge but it feels pretty strong when cranking the motor by hand. Spark looked fine.
 

Barnacle1970

Recruit
Joined
Jun 30, 2015
Messages
3
The roller is maybe 1/4 inch from the middle of the hashmarks on the cam at idle, but it never had any trouble running for the couple of times that we took it out. The only thing I noticed was a little bit high idle but no major smoke or running issues.
 

tblshur

Senior Chief Petty Officer
Joined
Aug 24, 2011
Messages
688
auto parts store will loan a compression gauge, adjustable spark tester 8 bucks may need carbs cleaned. good luck:joyous:
 
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