'73 Evinrude 115 - Weird starting problem

[BOAH]

Two different times, I've had a hard time getting the motor to start. It just cranks and cranks and won't fire. I thought I would check the spark so I pulled the top left plug (looking at the engine from behind) and cranked the engine and it immediately started without the plug! The plug was wet both times so I dried it off, put it back in and the engine started fine.

What do you think is going on and anything that you would recommend so this doesn't continue to happen?

Thanks for your help.

 

[Joe Reeves]

Re: '73 Evinrude 115 - Weird starting problem

Test for spark with all of the spark plugs removed.

The engine must crank over at least 300 rpms in order for the stator to energize the powerpack. A slow cranking engine will result in no ignition.

If your engine cranks slower than normal at times, remove and clean all cable and wire terminals associated with the electric starter, including the battery terminals, solenoid connections, and the negative ground cable at the powerhead. Make sure that you also clean the component that the cables/wires attach to.

It's always possible that the electric starter requires reworking also.

 

[BOAH]

Re: '73 Evinrude 115 - Weird starting problem

The batteries are pretty new and it seems like it's cranking pretty good. I don't know how to measure the rpms since I don't have a tach so I can't say for sure how fast it's turning over.

I guess it could be cranking just under 300 rpms when it doesn't start but again, I don't know.

Are you thinking that by pulling the one plug, the engine could spin faster giving it a spark to the other cylinders then?

I like your advice of cleaning all of the connections anyway. Won't hurt to do that. And I didn't know about it having to be over 300 rpms to get a spark.

Thank you for the advice.

 

[86 century]

Re: '73 Evinrude 115 - Weird starting problem

The other fellow is dead on with the possible bad connection. I had one with a bad cable that you could not see from the outside. I found it by feeling the wires after cranking as the wires corrode the resistance builds up as does the heat. Good Luck

 

[Dhadley]

Re: '73 Evinrude 115 - Weird starting problem

If pulling one plug allows the motor to start, Joe is dead on as usual. It's not spinning fast enough with all 4 in.