1974 85hp Evinrude timer base problem?

[supafly1232]

*** Please note new problem posted further down*** Hello. I have a '74 85hp Evinrude, model 85493. Just before we bought it the previous owner installed a new power pack and stator and verified that the coils were good. At first it ran great(for a day), then the next day i was driving along then suddenly the engine coughed a little. Then next time we tried to start it it would only run roughly with the warmup lever all the way up, when we let the lever down it died. We used a spark tester to see that we had spark problems, only spark on half the cylinders. A new timer base was installed, which seemed to help, but spark on all four cylinders was still intermittent. Finally we took it to a mechanic, he installed a new power pack and it ran great, again for only 2 days. The third time we tried it we had the same problem as we did before we took it to the mechanic after we had paid $800. What could be taking out the power pack, or is there a problem somewhere else. One note: the battery we were using was a little old, could that be arcing or jumping causing the power pack to go bad? Oh, also are their more than one part number of power packs that work? (our current one is 581895) Thanks for the help! np.

 

[Joe Reeves]

Re: 1974 85hp Evinrude timer base problem?

Disconnect the black/yellow wire from the powerpack. Tutn the ignition key to the ON position (engine not running). With a volt meter, see if there's any kind of voltage reading at that black/yellow wire (I suspect there is). If so, replace the ignition switch.<br /><br />What's happening is that a very slight battery drain is taking place at the ignition switch (through the ignition switch), throwing that slight voltage to that black/yellow wire. That voltage in turn is being fed to the powerpack circuitry via the black/yellow wire.... and that will destroy the powerpack.... time and time again.

 

[supafly1232]

Re: 1974 85hp Evinrude timer base problem?

Hey, thanks for the help... our battery was slowly draining. Should there be no voltage at all on that wire? I will get on that and check that out! Thanks!

 

[Joe Reeves]

Re: 1974 85hp Evinrude timer base problem?

There should be NO VOLTAGE to that black/yellow wire.

 

[supafly1232]

Re: 1974 85hp Evinrude timer base problem?

Hey, we checked it out and think we have .5V running through it, so we'll check that ignition switch. THANKS!

 

[Richok]

Re: 1974 85hp Evinrude timer base problem?

I have a 79 model 85 hp and had the same problem. I found the black /yellow wire rubbing inside the control box. Check your wires good before throwing the switch away.I took my switch out of the control box and got the black/yellow wire away from everything and did my electrical test. Good luck.

 

[supafly1232]

Re: 1974 85hp Evinrude timer base problem?

We replaced the ignition switch and that seemed to have fixed our power pack problem. But last time we used it, it was running along fine and just all of a sudden lost power. It will idile sometimes, a little more difficult in gear, but is quite rough, sounds like only hits all four cylinders once in a while. After testing the timer base, it is only putting out a .5V signal. Is that enough? (according to spec, i think the lowest allowable voltage is .5V?). The timer base was NIB when we got it, but is old, i guess they don't make them like this anymore. We tried adjusting the pickups closer, we got about 3V then, it ran ok just long enough to get past the no wake bouys then did the same thing as described earlier. Are we looking in the right direction (timer base)? Also, I've heard of a power pack that is adjusted to respond better to low voltage signals from the timer base, is that something we should look into? THANKS

 

[supafly1232]

Re: 1974 85hp Evinrude timer base problem?

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