1990 Evinrude Timer Base/ Sensor Coil Bad?

mark munro

Cadet
Joined
Aug 12, 2002
Messages
13
Hey all,

Trying to diagnose a no start problem and think it might be the Timer Base/ Sensor Coil, just curious for your thoughts.

Over the years I've had an issue where I came down to the boat, try to start it, and I have a no start with no spark. I have an extra power pak so I put it on and the problem goes away, BUT right away I put the "old" one that just wasn't running back on and it runs fine, arrgggh. I figured I was fixing a bad connection somewhere during the process of changing over paks but I could never figure out where the problem really was. This has happened a few times over the years.

The other day I was running WOT, which I rarely do, and I noticed it was missing a bit. Back off on the throttle and it seemed fine and idled fine. A few days later I went down to the boat and I had a no start with no spark. I changed my pak again but this time it didn't fix the problem.

I'm assuming that one of the paks is good so I tested the stator, output on both side is 130VAC. Tested the keyswitch/stop circuit, tested ok. Next I tested the Timer Base/ Sensor Coil, ohm test is fine. I don't have a DVA but I do have a digital storage scope so I put it on the proper connections for where I should be seeing a .2 to .5 Volt spike. What I see is a constant AC signal that approaches 9.5 Volts peak to peak, and that's with the ignition off and nothing running, odd. If I crank the engine I don't see anything but this AC signal. If I connect the negative on the scope to a good ground on the engine and connect the positive on the scope to the pins on the Timer Base/ Sensor Coil, it's 0 Volts sitting there and when I crank the engine I get some spiky noise in the 0 to 50 millivolt range but it does look like there's 150 milliVolt spikes every 300 milliseconds ......The book says I should see nothing in this test, bad Timer Base/ Sensor Coil?

Thanks,
Mark
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1990 Evinrude Timer Base/ Sensor Coil Bad?

Model #??? Lots of different models in '90
 

mark munro

Cadet
Joined
Aug 12, 2002
Messages
13
Re: 1990 Evinrude Timer Base/ Sensor Coil Bad?

Sorry, it's a 225 HP VEX225TXESS.

I was recently told that people usually swap out the power pak and the Timer Base at the same time because they've seen one blow out the other and visa-versa, but I have a hard time seeing a low voltage device like a Timer Base taking out a pak? MAYBE a pak taking out a Timer Base ......
 

mark munro

Cadet
Joined
Aug 12, 2002
Messages
13
Re: 1990 Evinrude Timer Base/ Sensor Coil Bad?

I'd like to update everone on my status with this problem. I've been REAL busy and haven't had an opportunity to work on this problem since my original post. In short I replaced the Time Base last night and she fired right up.
 
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