1977 Johnson 115 too much stator voltage?

Springcrik

Cadet
Joined
Apr 9, 2008
Messages
21
My 1977 Johnson 115 is currently having problems cutting out above about 2000 RPM. Due to the age of some of the ignition components, I had recently replaced the regulator and power pack but that didn't change anything. A good marine mechanic tested the ignition system with a DVA and found the timer base voltage is only about 20 volts, so we need to replace it. He also said the stator voltage was 440 volts and said that even though there is no discoloration or melted insulation, he recommends that it be replaced because the voltage is considerably above specs. Also said that high voltage seems to be a kind of early warning for stator failure on these old engines. I searched this forum and it seems the general consensus is "no such thing as too much stator voltage." I don't want to have more problems, but I also don't need to throw another $300 or so into this old engine needlessly. What do you guys that work on these engines on a daily basis think about high stator voltage.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: 1977 Johnson 115 too much stator voltage?

If you got 20 volts on the timer, the meter could be bad or incorrect setting. Since both reading are high, i would suspect the meter.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1977 Johnson 115 too much stator voltage?

Agree. The 1986 service manuals spec timer base output at approximately .3 volts. The minimum stator voltages spec at around 150 volts. The 1986 manual does not apply to your older engine, but I'd be suprised if these voltage would be that much different. Is your marine mechanic using a "peak-reading" voltmeter?
 

yamahale

Cadet
Joined
Apr 11, 2013
Messages
6
Re: 1977 Johnson 115 too much stator voltage?

A magneto can only produce less voltage than standard, it is impossible to produce more. You would have to increase the number of windings or the magnet strength to achieve that....
 

schematic

Lieutenant Junior Grade
Joined
Jan 12, 2008
Messages
1,102
Re: 1977 Johnson 115 too much stator voltage?

Have you verified the ignition to be the problem? Have you tested for intermittent spark at 2000 rpm?
 
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