1995 SPX Possible Rectifier Problem?

[eavega]

Hello All,

So I had a problem last night after the initial shakedown cruise of my 1995 SPX. Initial start was fine, put it in the water, and ran it for the better part of an hour through its throttle range (WOT, Idle, 3/4 throttle, etc). It ran great throughout its throttle range. No cavitation, no hesitation, no unexpected slow-downs or stops ( I stopped a couple of times to switch riders, and a couple of times I fell off). After getting it back on the trailer ready to go home and celebrate a successful first day on the water for 2016, I started it up one last time to blow any remaining water out of the exhaust system. It wouldn't start. I could hear the solenoid "Thunk", but nothing else. Checked the killswitch, tried again, "Click". No start. One last time, Pressed start button, "thunk", held it a second, then it started up. Ran until I killed it (15-20 seconds). To me that sounded like a weak battery although I don't know why it would be as that battery is always on a tender when not out on the water and it was. I checked the voltage and it was 12.5 or so. I left the multimeter on the battery and tried to start the ski. Voltage dropped as I would expect to just below 12, then bounced back to about 12.4. I don't see it increasing any, but the engine is running just fine. I don't know too much about the electrical systems on the Sea Doos, so I don't know if there is any drain on the battery when its running. What I would expect is that the voltage at the battery should rise to about 14V as the charging system would take over. That being said, I would also not expect a huge drain on the battery if all I did was start the ski a half dozen or so times...

Anyway, does this all point to the charging system, specifically the rectifier? What else should I be looking at? Any help would be greatly appreciated.

Rgds

Eric

 

[1983]

Measure voltage at battery with ski idling and report back what ya got.

When you say it bounced back to 12.4, did the engine start or was that just with engine off? If that 12.4 is with engine idling then i would suspect something in charging system is fault.


Rob

 

[eavega]

Okay, so this afternoon on the hose, prior to starting the battery reads 12.8v. Start the engine and voltage climbs to 13.25. Rev the engine and voltage climbs and settles at just above 14. Let it settle back down to idle and voltage stays at 13.9 or so. Shut it down and voltage begins to slowly come down back to 12.8. Sounds normal to me, so I have no explanation for why it wouldn't start at the ramp...

 

[jhjesse]

Starting system and charging system are two different things. Rectifier would have nothing to do with the starter. I am thinking by your description of the problem you have a bad connection i.e. Ground wire or positive cable corroded somewhere. The other possibilities are either starter going bad or solenoid.

 

[boxchevyman]

Hi I know I’m knew here and I have problems of my own I couldn’t figure out, but I did just have this exact problem you describe. It was my starter solenoid. It will still click however it will not let current through.
If you open up your grey box and while the problem is happening (not cranking) you jump the terminals on the solenoid you now know that the solenoid is bad.
I bought one on amazon for like 16 bucks. It completely fixed my problem.

 

[eavega]

Well, I'm going to the lake again this weekend to try to recreate conditions. I can't get the ski to not start up. One bump of the start button and it starts right up. Before I start replacing parts, it makes more sense to recreate the problem and then do diagnostics, otherwise I may end up replacing the stator, solenoid, battery, rectifier, or starter before I eliminate all the possible points of failure. Updates to follow.

Rgds
Eric

 

[eavega]

Starting system and charging system are two different things. Rectifier would have nothing to do with the starter. I am thinking by your description of the problem you have a bad connection i.e. Ground wire or positive cable corroded somewhere. The other possibilities are either starter going bad or solenoid.

I think I agree, except that if the rectifier is not working, then the battery is not charging. If the battery is not charging and you are continually starting the ski (as I was that day; switching riders, falling off, checking things out, having the killswitch pop inadvertently two or three times), you are draining the battery every time you start. There will come a time where you don't have enough juice in the battery to spin the starter. The ski will run all day long, as spark is being generated by the magneto. Starting, however, relies on power from the battery spinning up the starter motor. Weak battery = no start. I am going to go ahead and check the connections, though. I keep trying to run through the whole day in my mind to see what was changing versus running on the trailer. I have come up with at least three variables; 1. some water got into the hull (not a lot, probably less than a quart) that might have temporarily shorted something. Once the water was removed and the component dries out, short is gone. 2. Ran the ski for about an hour so something might have gotten hot, expanded and shorted out, then once it cooled down the short goes away. 3. Ran the ski through its paces so it experienced shaking and shocks it won't get on the trailer. Something might have gotten knocked around and made for a bad contact. Given that I could in no way recreate the issue on the trailer yesterday, I'm looking to an effect from the activities on the lake as the cause of the no-start on Tuesday.

E

 

[Coastiejoe]

Rectifiers can charge the battery fine and still be bad. Reason is, they can fail and output some A/C voltage. When they do they screw with the MPEM and still charge the battery.

 

[eavega]

Rectifiers can charge the battery fine and still be bad. Reason is, they can fail and output some A/C voltage. When they do they screw with the MPEM and still charge the battery.

But wouldn't that manifest itself in a poor running engine? missing or mis-timed spark? The engine runs well, idles, WOT, and is running at its top speed for this ski (47 MPH by GPS). The only issue was that when I tried to start it on the trailer after I got it off the water, I would get a click (starter relay, I assume), but no spin. Usually the motor starts with a bump of the starter. This time I finally got it to start after about the fourth try, and that time I pushed and held the start button for a second or two. I still got the initial click, then it seemed to get enough "oomph" to spin the motor. I have been unable to recreate the problem since getting the ski home.

E

 

[jhjesse]

Ok if you want to believe that are one system, it is your ski and you can do what you want.
You tested the rectifier and it is putting out 13.25vdc, therefore the rectifier/charging system is working. On to the next thing.
Usually when a starter or solenoid goes "thunk" with a good battery it is one of three things. Bad starter, bad solenoid, or bad connections. In your case it was working, then it wasn't, then it was working again. That tells me that you have a bad connection somewhere. Electrical parts usually either work or they don't. There is no inbetween. Sorta like being almost pregnant. Bad analogy, I know.
As I stated before it is your ski and you can do what you want.

Oh yeah I stated that they were two different systems...never said they were not interconnected.
Good luck I'm out.

 

[boxchevyman]

Take a look at this video it is helpfull for your problem.
https://youtu.be/n-Ar8A2Gzx0
It will also help you rule out what kind of problem you have. If for example you jump the solinoid and it works the you know your solinoid is shot. Or if you jump it and nothing happens you know its either a dead battery or your starter or a bad conection.

As a side note 12.3v is plenty to start a jet ski.
And I think your rectifier is totally fine.

 

[boxchevyman]

Double post.

 

[eavega]

Thanks for the help jhjessee, I agree with you. I think its a connection that may have come loose. That is the first thing I am checking, followed by the solenoid (as soon as I can reproduce the problem). Given the results of the test on the trailer, the battery is as charged as its gonna get, so the rectifier is not suspect anymore.

And I do understand that starter has nothing directly to do with the rectifier. Like you said, two different systems.

E

 

[Coastiejoe]

But wouldn't that manifest itself in a poor running engine? missing or mis-timed spark? The engine runs well, idles, WOT, and is running at its top speed for this ski (47 MPH by GPS). The only issue was that when I tried to start it on the trailer after I got it off the water, I would get a click (starter relay, I assume), but no spin. Usually the motor starts with a bump of the starter. This time I finally got it to start after about the fourth try, and that time I pushed and held the start button for a second or two. I still got the initial click, then it seemed to get enough "oomph" to spin the motor. I have been unable to recreate the problem since getting the ski home.

E

Yes, it would create a miss or power loss. I wasn't trying to suggest an answer, just adding that they can fail in multiple ways. Sorry about that.