Sport Jet 120. No spark.

[Baja120]

Just bought a 1996 Baja with a sport jet 120. I have no spark at the plugs. I found a wire from the stator that was coroded and spliced it back together and had spark for a short time. I have compression and I have tools and UEI meters. Just looking for somebody that might know a little more about these motors. Thanks for any help!

 

[Bondo]

Re: Sport Jet 120. No spark.

Ayuh,... You have a glorified Jet-Ski,...
Answers can be found in the Jet-Ski forum for your boat...

 

[jjzepplin]

Re: Sport Jet 120. No spark.

I did a lot of research on these boats before deciding not to buy one. Apparently they have a "force" type engine and they had their share of spark and stator issues. # 1 if your stator is damaged replace it. #2 if your stator is black replace it with a new red stator.Most of the issues were worked out by 1997. If your 120 is an "xr" model or is built after 1996 these were the better ones. But they are just large jet skis and have jet problems as well.Especially in salt water use. I have also seen the magnets under the flywheel become loose and affect spark as well. Check that when you REPLACE your STATOR.!!!!

 

[kend301]

Re: Sport Jet 120. No spark.

Zep is right they were plagued by stator problems , Post up which stator you have ( red or black) and I will post ohm readings for that one . One quick way to tell is the black stator has red and blue wires coming out of it going to the switch box and the red stator has green/white and white/green wires running to a rectifier then blue to the switch box. BTW if you do have a black stator I would replace it regardless of test results, It will fail .

 

[kend301]

Re: Sport Jet 120. No spark.

Here is some info to get you started :
Four Cylinder Engines
(1991-1996)
Four Cylinder Engines Using a Single Switch Box and Four Ignition Coils
No Fire At All:
1. Disconnect the black/yellow stop wires AT THE PACK and retest. If the engine?s ignition now has spark, the stop circuit
has a fault-check the key switch, harness and shift switch.
2. Disconnect the yellow wires from the stator to the rectifier and retest. If the engine has spark, replace the rectifier.
3. Check the cranking RPM. A cranking speed less than 250-RPM will not allow the system to spark properly.
4. Check the stator resistance and DVA output as given below:
Flywheel with Bolted in Magnets
WIRE Read To OEM RESISTANCE CDI RESISTANCE DVA
Blue Blue/White 5000-7000 2200-2400 180V or more
Red Red/White 125-155 45-55 25V or more
Flywheel with Glued-in Magnets
WIRE Read To OEM RESISTANCE CDI RESISTANCE DVA
Force Troubleshooting
Blue Blue/White OHMS :3250-3650 DVA: 180V or more
Red Red/White OHMS:75-90 DVA 25V or more
Red Stator
WIRE Read To OEM RESISTANCE CDI RESISTANCE DVA
White/Green Green/White OHMS:500-700 DVA: 180V or more
Red Stator Adapter
WIRE Read To OEM RESISTANCE DVA
Blue Blue OPEN 180V or more
Blue (Each) Ground OPEN 180V or more
NO SPARK OR INTERMITTENT SPARK ON ONE OR MORE CYLINDERS:
1. If the cylinders are only acting up above an idle, connect an inductive Tachometer to all cylinders and try to
isolate the problem cylinders.
2. Check the trigger resistance and DVA output as given below:
Wire Color Check to Wire Color Resistance DVA Reading
Purple wire White wire 800-1400 4V or more Connected
Brown wire White/Black wire 800-1400 4V or more Connected
Purple wire Engine GND Open 1V or more (*)
White wire Engine GND Open 1V or more (*)
Brown wire Engine GND Open 1V or more (*)
White/Black wire Engine GND Open 1V or more (*)
(*) This reading can be used to determine if a pack has a problem in the triggering circuit. For instance, if you
have no fire on one cylinder and the DVA trigger reading for that cylinder is low ? disconnect the trigger wire
and recheck the DVA output to ground from the trigger wire. If the reading stays low ? the trigger is bad.
Note: If #1 and #2, or #3 and #4 are misfiring, check the trigger as described above. The trigger uses two coils to
spark four cylinders. #1 & 2 share one trigger coil and #3 & 4 share the other trigger coil. Also, the switch box is
divided into two parts. The #1 and #2 cylinders spark on one half, and #3 and #4 spark on the other half of the
switch box. If the trigger tests fine by the chart above, but you have two cylinders not sparking (either #1 and #2 or
#3 and #4), the switch box or stator is bad.
3. If you have two cylinders not sparking (either #1 and #2 or #3 and #4), swap the stator leads end to end on the
switch box (Red with red/white and blue with blue/white). If the problem moved to the other cylinders, the
stator is bad. It the problem stayed on the same cylinders, the switch box is likely bad if the trigger tests within
specifications.
4. Check the DVA output on the green wires from the switch box while connected to the ignition coils. Check the
reading on the switch box terminal AND on the ignition coil terminal. You should have a reading of at least
150V or more at both terminals. If the reading is low on one cylinder, disconnect the green wire from the
ignition coil for that cylinder and reconnect it to a load resistor. Retest. If the reading is now good, the ignition
coil is likely bad. A continued low reading indicates a bad power pack.

PLEASE post test results prior to getting any parts , This is a general guide and sometimes results can take you the wrong way due to other bad parts effecting test results !

 

[H20Rat]

Re: Sport Jet 120. No spark.

Ayuh,... You have a glorified Jet-Ski,...
Answers can be found in the Jet-Ski forum for your boat...

not really...

he has an inboard boat that is powered by an OUTBOARD powerhead, connected to a jet pump lower unit instead of a prop drive. The 90/120 sportjets are force powerheads, the only difference compared to the outboard version is the crankshaft is slightly shorter. Other than that they are part for part identical. The SJ175's and higher are 100% identical.

To the OP... someone else beat me to it, 99% chance it is the stator. Very common for the first gen on those to go out.

 

[chronomania]

Re: Sport Jet 120. No spark.

Help!

I have a sport jet 90 that was running fine until starting it one day at the boat ramp.

While the engine was turning, it started shedding the flywheel magnets. I took the boat home and removed the flywheel. The flywheel magnets were all missing except for one (they appeared to be glued-on). The red stator was damaged from the magnet fragments. I purchased a new flywheel and red stator, installed a spark tester and cranked. No spark! I purchased a DVA adapter for my multi-meter and the highest reading that I am getting is 60 volts. I replaced the starter and battery to assure that I had maximum cranking speed and voila-----no spark and still only 60 volts! Is it possible that I received a bad (new) red stator or am I missing something obvious? Anybody in south Florida to recommend to take the boat to; I am out of ideas?

I have removed the flywheel three times to verify that I have aligned the stator properly. I have changed the trigger and voltage regulator and have disconnected the black/yellow wire from the rev limiter for testing purposes. The stator resistance tests within range (about 600 Ohms). Are there supposed to be six magnets (end-to-end) inside of the flywheel for a three cylinder (my old flywheel was too battered to tell)? This engine does not have a switchbox; the stator green/white and white/green wires goe directly to the coil assemblys.

I appreciate all and any information that you may offer!!!

Sparkless in Florida..........

 

[kend301]

Re: Sport Jet 120. No spark.

Chronomania , The tests are slightly different for the 90 vs the 120 , I am going to start a new thread for you called "Chronomaina Sport Jet 90" I will post some info you need in a few hours. I just want to keep these boats separate so no one tests something that may not apply to their boat and waste money on parts . Please start posting info in that thread.

 

[Baja120]

Re: Sport Jet 120. No spark.

Ok, I got the stator off and three of the magnets were stuck to it and it is the black one. Where is the best place to get the red stator?

 

[kend301]

Re: Sport Jet 120. No spark.

If the flywheel magnets have come off chances are you are going to need a flywheel also . I have heard of some people reattaching them with epoxy but I have little faith in that fix but I am told it does work. I also think on the 120 you will need a stator kit to update to the red stator. Best to call a parts place like Iboats to be sure you are getting the right parts.

 

[Baja120]

Re: Sport Jet 120. No spark.

Ok I have spark and have had it running and in the water. After fixing another problem I started it for a second in the shop and shut it off and then started getting ready to take it to the lake. Went to hit the key one more time before leaving and it just spun the rotor like it had no compression. After looking into that I found that the key for the rotor from the crankshaft was bad. Replaced it and now it acts like it has to much compression and will hardly turn over at all. I am guessing that the timing is off but I have no idea on how to change it or check it! Any help would be great! I do have a timing light and so on. I just know nothing about boat motors.

 

[kend301]

Re: Sport Jet 120. No spark.

Sounds like you got water in the motor from to much pressure , pull the plugs and see if water runs out. If so reduce your hose pressure when you try to time it . I will post proper timing procedure for out of the water in the next few hrs after I get home .

 

[Baja120]

Re: Sport Jet 120. No spark.

Is there a place to hook up a hose? I looked and could not find one. I had started it out of the water for only a few seconds and then I was going to take it to the lake. I have had the plugs out and nothing came out and the crank would turn freely. Thanks for the reply!

 

[kend301]

Re: Sport Jet 120. No spark.

Check battery voltage , Put the plugs back in and try to spin by hand , if you can spin by hand and not with the starter your starter may have past it's expected life span.

Timing info coming tomorrow morning . There is no fitting for the cooling hose , you must unhook the cooing Hose at the lower engine plate and insert an adapter into the hose and hook the hose to the adapter . Please read the first post Sport Jet Basics at the top of this section , you need to control flow or else you will flood the motor with water .

 

[Baja120]

Re: Sport Jet 120. No spark.

The starter was bad. I put the new one in and it turns like crazy but does not fire up. After turning it over for a short time it backfires and thats all I get. Could the timing be off? It has spark and is getting fuel.

 

[kend301]

Re: Sport Jet 120. No spark.

I fit is backfiring through the carbs something is hooked up wrong , Hook a timing light up to #1 and post timing readings !!

 

[Baja120]

Re: Sport Jet 120. No spark.

It is backfiring through the exhaust.

 

[kend301]

Re: Sport Jet 120. No spark.

Are you trying to start this boat out of the water without a flush kit hooked up ???

 

[Baja120]

Re: Sport Jet 120. No spark.

Yes but only for a few seconds.

 

[kend301]

Re: Sport Jet 120. No spark.

Take another compression test , you may have cracked or melted pistons by running it out of the water without a flush kit , Also the "backfire" is probably the boat trying to blow the ride plate off , Again from running out of the water without a flush kit , It only takes a few seconds. Also please check timing and post results and If you continue to try to start this boat without a flush kit , You are on your own as far as damage !