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1999 GSX limited 951 Engine, new Stator and trigger, no spark

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EPBlanchard

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Hello Everyone,

I've just finished up rebuilding the carbs, while I had the pipe off, I decided to finally fix the charging issue by changing out the stator and the sensor. After many hours and "modified" tools, I got it all back to together and now no spark on either plug. I have an old donor bike, so I cut the plug from it and tested the coil and trigger wiht this method:
Stator test:
There are 5 wires going into the front of the engine: 3 yellow, 1 yellow and white and 1 black and yellow.
The 3 yellow wires should have continuity (connection) between themselves and no continuity between any of them and engine ground.
Connect the ohm meter between the yellow/white wire and the black/yellow wire. They should read 190-300 ohms.

I also did the static test on the coils, which are good. Everything checked out... fuses are good front and back. anybody got any ideas? I hope its not the MPEM, but I'm running out of things to check....
thanks in advance for any advice -- Eric
 
Also - I just pulled the plug out of the MPEM to test the wiring harness going to the back... I had my lead on coil spade connecter and was probing around the plug. This seems odd, I get continuity across the all 4 bottom wires with that spade connector on the coil??? thats 2 white wires, a black, and a yellow/red..
 
this bike has 2 different coil units in the electrical box in the back..I changed the stator and sensor, I did not replace the coils, but they checked out
 
Yes but 97.5 and 98 951's used a single coil system. If the cup(is that the pick up you mentioned?) came off one of those early ones then it will not jive with your two coil system.
 
Most of the time there are 1 or 2 small ground wires that get attached at 1 of the front cover bolts. Are they attached?
 
no ground wires on the cover bolts on the 951, the ground location on the left front side with multiple ground wires just in front of the carbs.
 
Matt- just to be clear, I didn't use any donor parts from the other bike, just cut the plug off to be able to test the coil. The stator and trigger sensor are new...

Sportster- I will check to see if I have a signal coming from the trigger tonight and also confirm that I have all of the ground wires connected to that lug on the left side of the engine ( I believe I do though).

What about the continuity to the coil from those wires in the plug? one is a ground, 2 white wires are the coil signal, and the yellow/red is to the solenoid. I can't figure why they would show up when I test them against the spade on the coil.
 
What about the continuity to the coil from those wires in the plug? one is a ground, 2 white wires are the coil signal, and the yellow/red is to the solenoid. I can't figure why they would show up when I test them against the spade on the coil.

I'm unclear on what you're measuring here, maybe we can try concentrating on this.

I like the suggestion of making sure all the grounding lugs are re-attached, this item is easily missed b/c those ground lugs could easily hide themselves!
 
I'm unclear on what you're measuring here, maybe we can try concentrating on this.

I like the suggestion of making sure all the grounding lugs are re-attached, this item is easily missed b/c those ground lugs could easily hide themselves!

Here is the original post:
I just pulled the plug out of the MPEM to test the wiring harness going to the back... I had my lead on the coil spade connecter and was probing around the plug. This seems odd, I get continuity across the all 4 bottom wires with that spade connector on the coil??? thats 2 white wires, a black, and a yellow/red..
 
Thats not how you test things...and on jetskis you really dont want to be cutting and splicing wires. Just causes problems down the road.


Ok...so heres how to test this stuff. First, on 951s and 787s the stator has nothing to do with spark. Its the trigger/pickup. They can be tested by checking ohms (to make sure it hasnt got metal stuck to it, shorting it out) and then by putting a voltmeter on those two wires (yellow/blk, black/yellow) and cranking the motor. Worth a test...but its really to test for a broken pickup bracket. We know that isnt the problem.

Anyways...on the 951s you can check those two wires by pulling the big connector off the MPEM and cranking the motor by jumping the solenoid. Then you know the signal is good to the MPEM.

Then from there hook everything back up and go to the rear ebox. Pull the square connector off of the rear ebox and make sure it isnt corroded. Seen many corroded there.

Once that is checked, put a test light on each white wire from the coil, and the other to ground. Crank it over and it should flash. If it doesnt and you have checked everything above, its prob the MPEM.

I do have a used one in stock and ready to ship.

Lastly....make sure your battery is healthy. If it isnt, it can crank fine, but the Ignition will not turn on due to low voltage.
 
Thats not how you test things...and on jetskis you really dont want to be cutting and splicing wires. Just causes problems down the road.

Yeah, I think he only hacked out part of the stator harness from his parts donor ski so he could make his own test fixture and not hack up his riding ski.

3-16,3-17,3-18,3-19 will all have continuity if measured from the #3 MPEM harness connector, b/c the meter current would loop through the ignition coil and back through any of the other three through the common grounds of both coils and the starter solenoid coil. So this seems normal unless I'm misunderstanding.

And Minnetonka has good advice, but is it safe to assume the MPEM is receiving the trigger signal? Unless the MPEM receives this trigger pulse it won't ring the ignition coils, so we can't say the MPEM is bad unless we confirm it receives the trigger signal (IMO). I believe the trigger signal occurs 4x per revolution but not sure if that's really true or why that's necessary, seadoo wanted that way I guess?....

Here's the 2001 schematic, the ignition/e-box section is probably the same since it's the dual ignition coil configuration:
 

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  • 2001 seadoo 951 schematic diagram.jpg
    2001 seadoo 951 schematic diagram.jpg
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yeah I was saying the trigger its self since he just replaced it we can assume it wasnt broken off, and if there were metal chips on it they were cleaned before install. But yeah never assume on a seadoo...lol could have a corroded pin connection or a broken wire.

looks like 2-1 and 2-9 pins are the trigger.
 
seadoo trigger 1.jpgseadoo trigger 2.jpg

Gents,
Of course my seadoo shop manual CD just crashed....I think I have the test procedure for the trigger printed, I'll do that tonight. When I started this journey, it was running but running poorly, I assumed water in the gas (ethanol issues). I tested the stator and found that it was bad, so I ordered a new one. They accidently sent me the sensor assembly and gave me a good price on it, so I changed that to. I don't think there was anything wrong with the other one. Just to be sure.. is the sensor assembly the "trigger"? I believe it is, but the parts list doesn't call it a trigger.
The only other thing I thought of is that I didn't know the correct orientation of the trigger, is it possible that putting it in wrong would cause this? the two little prongs on the sensor are facing toward the engine, but you can install it 180 degrees differently than I have it. If you look at the sensor and the little bracket that holds the assembly, I installed it with the curved side toward the stator and the black box pointed upward or torwards the engine.. its hard to tell from the picture. I attached 2 pics of the assembly.

would you guys happen to have a picture of how it is supposed to be installed?
 
I don't know why I didn't catch this earlier, moving this thread to the 2-stroke PWC section.

Lou
 
Here's the photo showing the 947 trigger sensor orientation from the 2001 service manual, maybe this helps:

Mr Sportster, that does help.. sort of. It confirms that I am an idiot and put the frickin thing in backwards. I had no idea what the sensor was for. So now, after I beat my head against the wall for a while, I have to take the pipe off again to get to the stator cover. I just put a brand new gasket on the exhaust manifold and also put red gasket sealant on both sides.. what is your opinion on reusing the gasket? my local dealer only sells the kit from sea doo for 50 bucks (comes wiht the bolts and boot).
 
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