Failing Regulator / Rectifier Johnson 2001 150 hp 2 stroke?

Johnalcon

Cadet
Joined
Jul 24, 2007
Messages
22
I have a 2001 Johnson 150 hp, model J150PLSIF. I have owned it since new and it is spotless. It starts and runs most of the time on the water. However, it has failed to restart 3 times in the last two outings, one resulting in a tow to the ramp. On these occasions, it cranks and cranks and won't "hit". There was no spark to any plug. After reading many forums, I went through the "No spark to any cylinder troubleshooting list" that CDI provides. By unplugging the yellow and yellow/gray connector between the stator and reg/rect, the motor immediately pops right off and starts. When I plug that connector back in, the motor runs great again for many start ups and cruising. So, at this point it is intermittent, but I predict will return again.

I tested the reg/rec with the diode function on my digital multimeter ($30 model). red probe to red wire and black probe to yellow and then to yellow/gray with no change to the meter display.

Next, black probe to red wire and red probe to yellow wire, .422. Black probe to red wire and red probe to yellow/gray wire, .410.

Also, recently my tach won't read above 4800 rpm. When i run WOT, the motor sounds like it is running the normal 5200 rpm. When i trim too high and too low there is an audible change in motor rpm, but the tach remains on 4800 like it refuses to read anything higher.

I have checked and rechecked connections and I have a good, fully charged battery. The engine is entirely OEM parts. Can a reg/rec fail intermittently like this and cause the engine to lose spark? I have a Clymer manual I have been referring to, but there is little on testing the reg/rec. I have tested all other ignition components as much as I can without a peak reading voltmeter and other specialized tools.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Failing Regulator / Rectifier Johnson 2001 150 hp 2 stroke?

It's almost impossible to find a problem like yours if everything is working properly, unless you throw parts at it and get lucky. I think you are going to have to wait till it fails and go through the checks.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Failing Regulator / Rectifier Johnson 2001 150 hp 2 stroke?

If you get a proper meter, you can find the problem. You could at least check the ohms between the 2 yellow wires. Easy enough to check the pack output voltage to each ignition coil, primary side.
 

jimmy rorrer

Recruit
Joined
Aug 27, 2014
Messages
2
Similar issues with 1997 150hp fastrike. Rectified bad again! Two in a year...wonder if thermostats being stuck open would cause rectifier to go bad. Been stuck open for at least two years, was told would not hurt anything???
 
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