Ringerd's Sport Jet 120 spark problems

Ringerd

Cadet
Joined
Feb 2, 2010
Messages
18
120 Sport Jet in a 1996 Sugar Sands. Motor has been replaced and according to the serial # (OE122548) the motor is a 1995. Boat is new to me. Tried it out and everthing seemed fine.
Get it home and after 2 trips, problems.

Today developed a miss at slower rpms. Would speed up and it would smooth out. After a few minutes everything seemed okay. Was running about 2/3 throttle and engine died. It was like you turned the switch off.
Still cranked, but no firing.

Back at home, checked for loose wires, found one ground loose, but still no luck.

Borrowed the neighbors spark tester and found out the following.
# 1 cylinder, constant spark but somewhat yellow.
# 2 cylinder, bright blue but intermitent after a little cranking. If cranked long enough, it stopped.
# 3 cylinder, nothing. Even switched spark plug wires to eliminate them.
# 4 cylinder, constant bright blue spark.

I will find out about my stator, do the other tests, and get back here when done.

I have the shop manual and did disconnect the black/yellow from the switch box and also from the rev limiter. It had no effect. I got the same results.
 

Ringerd

Cadet
Joined
Feb 2, 2010
Messages
18
Re: Ringerd's Sport Jet 120 spark problems

While waiting on multimeter I found out I have the red stator, but there are 2 blue wires connecting to the switchbox. One solid blue and one blue/white. Is this correct?

Also today I swapped the #3 and #4 coils. #4 still fired on the first try and then it would not crank. Checked, no fire to ignition switch. Fire at the solenoid. Ran down the red wire going into the regulator. Unplugged and replugged still nothing. Saw another red wire in the same wiring harness. Tried to run it down but couldn't see where it went. After moving that harness, the engine would crank but now there is no spark on #3 or #4.
I will start looking for bad connections or shorts.

Any other suggestions?

Don't everyone talk at once, lol.
 

Ringerd

Cadet
Joined
Feb 2, 2010
Messages
18
Re: Ringerd's Sport Jet 120 spark problems

Answers to the 6 questions for: OE122548, 1995 120hp sport jet with red stator with stator adaptor (replacement?) and conventional coils.

1. Checked grounds. Okay
2. Battery: 12.8 volts
3. Disconnecting black/yellow, made no difference in spark.
4. Disconnected yellows from voltage regulator, made no difference in spark.
5. Stator ohmed 685 ohms.
6. Trigger
White/black to brown 843 ohms
White/black to purple 8300 ohms
White/black to white 8310 ohms

I have now lost the spark on #2 cylinder. Down to #1 and #4 only.
 

calledinsick

Petty Officer 2nd Class
Joined
Jul 13, 2010
Messages
160
Re: Ringerd's Sport Jet 120 spark problems

My experience is with the 90, but a trigger for a 120 should have 4 wires (5 including the black: black, blue, brown, white, purple).
Purple - #1
White - #2
Brown - #3
Blue - #4
 

Ringerd

Cadet
Joined
Feb 2, 2010
Messages
18
Re: Ringerd's Sport Jet 120 spark problems

Boat fixed.
Switch box was bad. Did funny things before it finally quit all together.

Back on the water.
 
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