1973 evinrude 70hp outboard engine

[Jay_396]

I cranked the engine like normal and it ran for about five minutes, and went dead with me. I tried to start it back and it would not crank. <br />Coil #3 has weak fire . Coil #1 & 2 has no fire.<br />Can anyone guide me to fix the problem or give me any helpful hints? Also would like to diagram to go by, if anyone has it.<br /> Thanks,<br /> Jay_396

 

[OBJ]

Re: 1973 evinrude 70hp outboard engine

Hi ya' Jay and welcome to the forum.<br /><br />First, get a service manual for the engine if your going to do the work yerself. Iboats have generics or if you want OEM, go that route. OEM's are a little more detailed. Both types carry wiring diagrams<br /><br />Weak spark no spark. Three possibles. Power coil in the stator assembly under the flywheel is bad although it would seen it's OK as you do have a little spark.<br />The timing sensor under the flywheel which tells the power pack when to fire is gone south.<br />The power pack has bit the dust. I would tend to go with the power pack although I would check the output of the timing sensor first to see if it's generating voltage. This is where a manual would help direct you as to what leads to check. <br />Keep us posted as to your progress.

 

[OBJ]

Re: 1973 evinrude 70hp outboard engine

Just remembered one more thing, your engine is a little newer than 73'. There were no 70hp's till 74'. Post your model number and we can tell ya' or do it yerself from the site below.<br /><br /> http://mitglied.lycos.de/old_omc/evinrude.html <br /><br />

 

[Jay_396]

Re: 1973 evinrude 70hp outboard engine

The model # to the evinrude motor that i have is 70473-M<br />When i tested for dc voltage, i got 1.5 to 2 volts out of sensor wire # 1, 2, and 3, that goes to one side of the power pack. ( this was while turning the engine over.) On the other side of the power pack is where the coils 1, 2, and 3 are hooked up and there is no dc voltage there at all. at the ignition wire that goes to the power pack that is yellow striped has 12.8 volts dc. <br /> thanks, <br /> Jay_396

 

[Jay_396]

Re: 1973 evinrude 70hp outboard engine

I think that we have just about found out that it is going to be the power pack. Just in case does anyone know for sure how to test the power pack? We mainly deal in electronics, not sure in machanics. We appreiate everyone's help.<br /> Thanks,<br /> Jay_396