Evinrude 70

[Jennifer1234]

I have an evinrude 70, model 70773S, serial J0011314.

Can anyone tell me what year it is?

Major problem is that it goes into a slow down when run at high speed (doesn't happen at 3/4 or lower just full throttle). Then suddenly with no interference from me it will pickup again and run great for a few mins., then bog again. Replaced gas, cleaned gas tanks, new carbs, now gas lines, filters, separators.

Hope someone can help, Jenn

 

[djeady]

Re: Evinrude 70

You did replace the line from the tank to the motor - sounds like it could be sucking air. Also, check the vent on the tank - make sure you are not building up a vacuum.

Could also be a coil failing under load.

 

[JB]

Re: Evinrude 70

That is a 1977 model, Jenn.

Sounds to me like it is dropping a cylinder, then picking it up again. I would call that an ignition problem. Since it only happens when at WOT I would look for a heat related sensitivity in one of the coils. See what happens at idle if you apply heat to each coil with a hair dryer. If that offers no result try the rest of the ignition system. Let us know what you find.

To bad you had to experience this truth: Changing parts is the most used, most expensive and least effective troubleshooting technique known to man.

 

[wilde1j]

Re: Evinrude 70

Hey JB, but you can eventually get a new motor!