Johnson 120 V4 1990 probably ignition problem

[duxducis]

Hi guys <br /><br />Can anyone explain me how to check stator condition? I did ground and ohmmeter test and that was fine. I measured voltage on 2 pin Amphenol connector between stator and power pack and got only 95 volts when I cranked engine .<br /><br />I am trying to determine stator condition, because I have problem with my outboard. <br />Everything started last summer at WOT. Engine has loss of power after 30 seconds at WOT. Than the problem arised above 4000 RPM. I could drive it on 3500rpm for one hour without problem, but when i went above 4000 it started to lose power only after 30 seconds. Several days ago I started new season, and same problem arised again. It started more often and on low RPM. I noticed that problem starts when engine reachs operating temperature. It sounds like one cylinder goes off,than another and than shuts off. Then I must wait for 5-10 minutes until i can start my engine again. <br />BTW no overheating alarm, and I think there is no overheating because I measured temperature on each power head when problem happens, it was below 40 degrees Celsius(as I previously thought it was S.L.O.W. system) Also have new impeler and stady stream of water coming from the engine.<br /><br />I ordered 4 ignition coils, power pack, rectifier, temperature switches, thermostats, diode kit... As I am waiting my order I am considering to order stator and timer base. Any suggestions, because I do not want to spend more money than needed? <br /><br />P.S. I must admit that last season I started to use NGK plugs BPR7HS, because I didn t have Champions. Now I have two sets Champion plugs on my table in front of me and planning to install them with the rest of the parts. I have QL77JC4 and QL16V. So which set should I install?

 

[duxducis]

Re: Johnson 120 V4 1990 probably ignition problem

And, is it possible that stator works fine when motor is cold and than after heats up to go bad?

 

[fishdog4449]

Re: Johnson 120 V4 1990 probably ignition problem

What makes you think it's electrical related? Sounds like fuel restriction of some sort when you mention not able to reach WOT. For that check fuel filter, carbs.
Power pack that is starting to fail could be intermittently affected by heat I've been told, I think more so than the stator.

On a side note, 104 degrees F sounds too low. I believe operating temp for that motor is 140. Check thermostats to make sure they are not stuck open - there is a very likely possibility of engine damage with the engine operating too cold.

 

[Daviet]

Re: Johnson 120 V4 1990 probably ignition problem

You're spending a lot of money not knowing what the problem is.
Use an inductive timing light and check each plug wire to see if you are actually loosing spark on any plug wires when the problem happens.

 

[175se]

Re: Johnson 120 V4 1990 probably ignition problem

I would use the QL77jC4 gap at 30, in my opinion the 16v fouls to much. I had new ones in mine after 6 hrs. two fouled out, six miles to go thought I lost the motor.