Trouble with 1996 Johnson 25HP 3CYL

brianc

Recruit
Joined
Oct 14, 2008
Messages
1
Problems started after I replaced the voltage regulator. I was out on the water when I noticed smoke coming from under the hood, the voltage regulator had got so hot it had started to melt the back of the regulator. The key start no longer worked. So I replaced the voltage regulator from a company called CDI. The key start works and all seemed to be good.
I took the boat out on the water and after about two to three miles of running the motor shut off (instant death) just as if I turned the key off. The motor would start right back up but do the same thing again. After this happened several times, the only way it would stay running is if I kept the motor either at idle or slightly above.
I took the motor into a marine mechanic where I had the water pump replaced and a leakdown and compression test done, this revealed that the motor was like new. He also tested the key switch and the safety tether, all good. This is an intermittent problem that apparently is hard to test because when it dies it will start right back up. The marine mechanic said the problem was probably the stator or the CDI unit(computer module). The problem I have with this, is that both pieces are about $200 to $300 each.
Any suggestions? Please help
 

OMCdinosaur

Recruit
Joined
Jun 13, 2011
Messages
5
Re: Trouble with 1996 Johnson 25HP 3CYL

Problems started after I replaced the voltage regulator. I was out on the water when I noticed smoke coming from under the hood, the voltage regulator had got so hot it had started to melt the back of the regulator. The key start no longer worked. So I replaced the voltage regulator from a company called CDI. The key start works and all seemed to be good.
I took the boat out on the water and after about two to three miles of running the motor shut off (instant death) just as if I turned the key off. The motor would start right back up but do the same thing again. After this happened several times, the only way it would stay running is if I kept the motor either at idle or slightly above.
I took the motor into a marine mechanic where I had the water pump replaced and a leakdown and compression test done, this revealed that the motor was like new. He also tested the key switch and the safety tether, all good. This is an intermittent problem that apparently is hard to test because when it dies it will start right back up. The marine mechanic said the problem was probably the stator or the CDI unit(computer module). The problem I have with this, is that both pieces are about $200 to $300 each.
Any suggestions? Please help

these engines have the worst cdi pack of any model (besides all of Merc switchboxes lol), starting right back up usually rules out a stator. have your mechanic use the factory test harness with his peak reading voltmeter and note the power coil output when the stalling occurs, any output after stalling (as motor is winding down) rules out stator issues. If you are not sure of ignition loss, run the motor on a 50:1 tank and see if it happens again. 95% of the time it is the crappy cdi box, which unfortunately the CDI corp.aftermarket part has copied the same vulnerabilities, which no one will explain to you.
 
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