'77 85HP Evinrude no spark, running diagnostics

[tdimichele]

'77 85HP Evinrude is not giving me any spark. I picked the boat up last fall and was told there was no spark. There was no key, so I hot wired...still no spark. I replaced the ignition switch today in case I hot wired incorrectly...still no spark.<br /><br />I have the Evinrude repair manual. I followed the wiring schematic's and triple checked all connections. Aside from missing the temperature sensor in the left bank, everything looked good.<br /><br />I read the test procedure's for ignition diagnostics in the manual. The procedures require the Evinrude S80 or M80 neon test light. It is expensive, so I was wondering if there were other diagnostics I could run to find the cause for no spark.<br /><br />I have tested the Sensor wires going to the powerpack with a multimeter. The reading changes on all 4 sensors going INTO the powerpack. The reading does not change on any of the outputs going to the individual coils. There was a spare powerpack with the boat. I changed and retested with the same results.<br /><br />Can anyone point me to some step-by-step diagnostic tests that I can perform without the M80 or S80?

 

[Indymike]

Re: '77 85HP Evinrude no spark, running diagnostics

Try these two links... Rapair<br /><br />and web page <br /><br />They should help.

 

[ezeke]

Re: '77 85HP Evinrude no spark, running diagnostics

Have you tried temporarily disconnecting the black and yellow kill wire at the powerpack? If not, try it. If the motor starts you will not be able to stop it with the key, so be prepared.<br /><br />If you look at your service manual's specifications sheets, you will see that the motor needs to be at 250 RPM for ignition. That is nonsense, you need 300 RPM. If your battery cables are old, replace them. If your battery is less than 650 cca marine deep cycle and fully charged, you have the wrong motor. <br /><br />Your ignition system is entirely dependent on a fully charged battery turning that flywheel, and all the diagnostics in the world will not get you a spark without it (unless the spark plugs are out).