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RSRBOB
RSRBOB, Technician
Category: Boat
Satisfied Customers: 1078
Experience:  Former Yamaha Factory Service Rep, Dlr Line Tech, Serv Mgr, G/M
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I've went through 3 stators in three months. What is going

Customer Question

I've went through 3 stators in three months. What is going on with my LS2000 Yahmaha.
Submitted: 1 year ago.
Category: Boat
Customer: replied 1 year ago.
I put each engine on separate batteries....seemed to work fine but then the tachs and feul gauges quit working and occasionally I would go to accelerate and the engine would rev but I would get no power output. Switched to same battery again and all seemed well. Then out yesterday while accelerating it revved and got no power out out and then lost the engine again. I know it's the stator as this is the third time.
Customer: replied 1 year ago.
I've checked all the plug wires and they are good. All the plugs are good. Before the stator starts to go bad I notice that I have to slowly accelerate then back off then go forward again to get the engine to "shift gears" so to speak. That's prob some carb work needing to be done though.
Customer: replied 1 year ago.
I've switched entire CDI boxes as well. The last stator literally exploded inside the front of the engine and the grounding wire in the flywheel cover exploded.
Expert:  RSRBOB replied 1 year ago.

Hi and thank you for your question.

This is a most curious problem, especially your last statement that the last stator exploded. Considering the stator doesn't spin, that doesn't make sense. If the stator windings were damaged, something extraneous (foreign object) got in the stator flywheel/rotor area and got caught between them and damaged the windings.

I do have some questions that I need answered.

Why was the first stator replaced, meaning did it have insufficient electrical output or was it physically damaged?

Have all the stator failures been on the same engine?

Have you taken the cover off to inspect the stator this time?

Are you replacing the stator yourself or having a shop replace it?

What year is your LS2000?

Please understand I am not trying to point fingers here at who's to blame, I am merely trying to help you get to the bottom of the problem so you can enjoy your boat again. I am happy to share my experience with you but by no means am trying to belittle you or insult you. I am just trying to leave no stone un-turned. As professional technicians, sometimes customer information helps us diagnose a problem, sometimes, based on experience, we can tell by the resulting damage as to why a component failed.

Let me know the answers to those questions and we can move forward from there.

Thanks,

Customer/p>
Customer: replied 1 year ago.
The Ls is a 2001. My hubris was killed many years ago so I don't get insulted easily lol. I have installed the stators. First time it was due to out of tolerance wires impedance. The second time was the same thing. When I took the engine apart the glue stuff around the windings had fried and the debris from it left residue all around the fly wheel and flywheel cover. The ground wire for the stator had literally exploded lol. I put the third stator on after cleaning and inspection of everything. Worked fine and put each engine on its own battery. Instruments wouldn't work on split batteries so after about 22 days I put them back on the same battery. Got a days worth of riding and then in the middle of an acceleration I got the feeling I got when the other one blew. The feeling of sadness of a dual engine motor with only one working. To top it off my steering helm finally gave out at the same time. I had a few water sodas left so I waited and got towed to shore.
Expert:  RSRBOB replied 1 year ago.

Thank you for the additional information.

It sounds like the stator is overheating, causing the discoloration and getting "fried".

Exactly what do you mean when you say out of impedance, because I am not aware of Yamaha providing any impedance specs on anything relative to an ignition system. Also, there are multiple coils in the stator, and if you were able to find a coil out of spec, which one was it?

Thanks

Customer/p>
Customer: replied 1 year ago.
When I say impedance I mean the ohms. I will dive in it tomorrow and send you the readings
Expert:  RSRBOB replied 1 year ago.

Thanks. Typically when the stator overheats like that, it is being overworked, which would indicate battery problems. In addition to the previous question, were you having battery problems that prompted you to try 2 batteries? Were they ever both connected when you had one stator fail? Also, just for clarification, they have all been on the same engine too?

Customer/p>
Customer: replied 1 year ago.
I switched to two batteries because initially the stator issue led to me killing the battery while starting. So if I had each on the own battery I would at least have one engine. I never had a stator fail on separate batteries. Only when on the same. The instrument panel wouldn't work when on split batteries either so I couldn't watch my tachs.
Expert:  RSRBOB replied 1 year ago.

Thank you for the additional information. For the stator to overheat, it has to be overworked. Have you checked your rectifier to see if it has a problem?

Customer/p>
Customer: replied 1 year ago.
I had originally and there was no issue
Expert:  RSRBOB replied 1 year ago.

ok

Customer: replied 1 year ago.
Any other advice?
Expert:  RSRBOB replied 1 year ago.

Still waiting on the results of the current stator readings. You were going to get them for me so we knew which windings were failing.

Customer: replied 1 year ago.
When I do the rest on the charge coil I get 0 resistance and the mauls calls for the readings listed
Customer: replied 1 year ago.
Pulsed coil gives me 270 on average
Customer: replied 1 year ago.
Exploded
Expert:  RSRBOB replied 1 year ago.

I have the service manual, so I don't need pictures of it. Just the info. The charge coils are open. But we don't know what failed on the others?

What about the lighting coil? It is going to have to be replaced no matter what, but I suspect something other than the charge coil is causing the problem.

Customer/p>
Customer: replied 1 year ago.
The lighting coil is part of the stator correct? It's the two green wires?
Expert:  RSRBOB replied 1 year ago.

Correct. And here is why I am questioning that. It is the only coil in the stator that the load changes for. Therefore, it becomes my suspect to cause the symptoms you are getting.

Customer: replied 1 year ago.
I ordered a new stator. So when it gets in what do I look for before failure. Is that an answerable question?
Expert:  RSRBOB replied 1 year ago.

You can check the AC output, and especially check the amps being put out by the rectifier.

Are you putting OEM Yamaha stators in it or aftermarket? If they are aftermarket, you might be the victim of inferior quality parts.

Customer/p>
Customer: replied 1 year ago.
I am buying them as oem replacements from http://www.jetskiplus.com/new-yamaha-stator-generator-many-wave-runner-xl1200-gp1200-suv1200-gp-xl-1200.html
Customer: replied 1 year ago.
Could I be getting bad ones?
Expert:  RSRBOB replied 1 year ago.

Yep, you sure could. Have you called them about a warranty?

Expert:  RSRBOB replied 1 year ago.

Yep, you sure could. Have you called them about a warranty?

Customer: replied 1 year ago.
Yea. They don't do warranty on electronics. Kinda pissed me off but hey I get it. If this one fails then I'll know to find another dealer. I'm not a boat guy but I understand engines and electronics. It keeps stumping me. I can't find a grounding issue anywhere. It seems to be this.
Customer: replied 1 year ago.
The magneto pulled the stator against the wheel and ripped the bolts out of the flywheel cover. The amount of force to do this was impressive.
Expert:  RSRBOB replied 1 year ago.

Well, I notice the aftermarket ones are $97, factory is $328. It makes me wonder where they are cutting the corners to be able to sell it for less than 1/3 the price...............

Expert:  RSRBOB replied 1 year ago.

Wait a minute. You just said the magneto (flywheel magnets I presume) pulled the stator against the wheel (flywheel)? I am not buying that for a minute. If the stator hit the flywheel, the bolts had to come loose. This is different from an electrical failure. Are you using hi temp loc-tite to put the stator bolts in the cover? Are you torqueing them to spec?

Customer: replied 1 year ago.
I used the red loctite 242. I torqued them to 35ft/lbs was that not suffice? Didn't see a set number in the manual. This only happened once.
Customer: replied 1 year ago.
If I'm doing something wrong please let me know!
Expert:  RSRBOB replied 1 year ago.

242 is not heat resistant. They are 6mm bolts that hold it in. 6mm bolts generally torque to 84 INCH Pounds. Are you sure you didn't torque them to 35 IN #? They would not take 35 Ft lbs without snapping off. If you did torque them to 35 in lbs, that would explain them coming loose. I am trying to help here, but keep getting more and more pertinent details rather inadvertently. I think we may have just gotten to the bottom of it, the stator is coming loose and hitting the flywheel and shorting out.............

Customer/p>
Customer: replied 1 year ago.
I will double check. This might explain this recent stator issue but still leaves me wondering about the first/second that failed. I will take t to a dealer and have them look over this whereas if it's something I'm doing that's cause them to go bad I'm not going to keep doing it. Thanks for all your help!
Expert:  RSRBOB replied 1 year ago.

You are most welcome. At this point, my best guess was the first one just went, the 2nd was of questionable quality and the 3rd was mechanic error. I can't guarantee it, but, highly probable.

Best of luck and if you have any more questions, feel free to ask.

Customer/p>

BTW, I checked the generic torque chart in the specifications section of the service manual, and even a 12 mm bolt (17mm hex, twice he diameter of the bolts for the stator) doesn't have 35 ft lbs of torque.

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