SOLVED 2 new rectifiers, both are DOA?

[RG123]

I'm having an electrical issue (I think it's mostly electrical) with my 1996 GTX, just looking for some advice.
-Background: boat is a 96 GTX, stock, with fully rebuilt carbs and genuine mikuni parts, pop off set to 32 and 32, fuel selector and water separator filters are all new.

-The problem: Bogging hard down low around 2600-3000 RPM. Upper RPM seems to be unaffected. I can be patient and gradually try to nurse it through the boggy zone, gradually going deeper and deeper into the throttle, and backing off if it seems close to dying. Eventually I can nurse it up to high enough RPM to hit WOT and it will get through the bog, and then work fine staying at 40-100% throttle. If I don't shut it down, It's much easier to get through the boggy zone. This has been an issue since last year, but I unplugged the rectifier red wire, and it ran much better. Because of this, and seeing others having similar issues caused by a rectifier problem, I figured it was the rectifier, and ordered 2 Titan rectifiers from OSD. (Given that there aren't any really reliable ones available, I figured it was best to have a back up).
I didn't get to ride again until this season, so I tried the first one out. Problem was still apparent, but not quite as severe. I changed the rectifier to the other new one, expecting a better result. This time the problem was worse, and the rectifier seemed to be extremely hot to the touch.
-The testing: I tested the rectifiers by putting a voltmeter on the battery leads with the ski running, per the shop manual. I had checked all the connections and fuses in the front and rear electrical boxes, and everything looked good. With the ski idling, voltage was 12.8v. Revving the engine to 5K resulted in NO change, still 12.8v. Same result when I installed the 2nd new rectifier.
I checked the Stator leads per the manual. (Caveat: instead of using the special Sea Doo pigtail recommended by the manual, (PN 295000136) that's hard to find and expensive), by tracing the wires of the plugged in Stator to the bullet connectors in the forward electrical box, and used those. All yellow lead-yellow lead resistances were 0.9 OHMS (specs in manual are 0.1-1.0). All stator wires resistance to ground were open (other than the grounds), so the stator is within specs.

So I have 2 new rectifiers, neither are charging the battery at all, and both get really hot when the engine is running. I don't see how they can be connected wrong. All the fuses and connections are good. Am I just unlucky and got 2 bad ones? I ordered another one from SBT that looks different and is more expensive, hoping for a different result.... thanks in advance.

 

[JC-SUPERJET]

First, check the Battery. Load Test it. It must be able to accept the Charge coming from the Rectifier or else the Rectifier is going to bake.

Sometimes the Battery Cell Internal Plates break inside or the NEG or POS Post Internal Solder Connections crack or break too.

A Healthy Battery is critical for the proper operation of PWC Electrical Systems, especially Seadoos.

Buy a good Battery. Expect to pay more than $100 bucks. Don't skimp on Batteries. Autozone sells a good Powersport Battery. Pay attention to the Warranty Period. If it says 2 years, then it'll last 2 years. Replace it then.

Buy good Rectifiers, not Chinese Knock-Offs. OSD Parts sells them.

 

[RG123]

Battery is brand new, and seems to be good. - 320Amp Powersport AGM Duralast from Auto Zone, 3 year warranty. Charges fine and cranks the engine strong. Forgot to mention that.

These two rectifiers I did buy from OSD, Titan Brand. They don't sell their "Heavy Duty" rectifier for my ski, unfortunately. Just these. I would spend much more if there was a clearly superior product out there. I'm hoping that the one from SBT will solve the problem - if it is just the rectifier.

 

[etemplet]

I got a brand new battery from Auto Zone that was crap. I fought the ski for a couple of hours trying to figure out what was wrong with the engine I just rebuilt. I tried all sorts of stuff even jumping the battery with a 1000 CCA batter and it would not turn the ski over. For some reason I installed an old battery and the ski fired right up.

I can tell you that 32PSI Pop-Off caused problems with my skis... both of them and both ere 96/97 GTXs with the 787. You likely do not have genuine Mikuni Needles and Seats and the Black Spring. once you install that... the pop-off will end up around 36-38psi and the ski will carburate better. You could also have an issue with the fuel ports inside the carb barrel. I mention this because sometimes we head down the wrong path and these skis are sneaky.

There is a voltage check you can do on the Mag while the ski is running. It is in the manual and much easier and quicker than pulling the carbs.

Getting back to the carbs.... it took me 5 times pulling the carbs on both my skis to get them working correctly I started at 23psi pop-off and each time I raised it the carbs did better. Even at 30psi I had issues. Good Luck !!

 

[POPPS]

Since you are able to “feather” it up to speed,,,seems like carb starvation,,,if the ski dies when you pin it from a standstill,,,the popoff is too high,,,therefore, ,I suspect the pilots being too low..,,pressurize the carbs and look for external leaks,,,
if the regulator was going,,,the ski would be troubled throughout the entire rpm range

 

[RG123]

So the first problem is fixed! I got the new (third) rectifier from SBT in the mail today, and installed it. Now, voltage at the battery with engine off is 12.8, and at 5000 rpm it is 13.4. The rectifier is working, no more dead batteries. Lesson is: AVOID Titan brand rectifiers. 2 out of 2 were DOA for me. Not only that, but they got smoking hot after only a minute of use. Look at the screw protruding from the bottom, preventing good contact with the metal base of the electrical box to promote cooling.

The SBT rectifier looks to be better quality overall.

I will adjust my pop off on both of my skis to around 36-38 to see if that helps the bogging down low.

Titan rectifier:

 

[RG123]

Update number 2: Second problem is fixed as well. I adjusted the pop off to 38 on both carbs (I don't think the new black springs I previously used were genuine Mikuni parts, the pop off chart lists it at 38 and they were both around 32). I had to stretch the spring a tiny bit to get the pop off right, and I know you aren't supposed to stretch or cut the springs, but I didn't have time to wait for new springs in the mail to get the ski working. Reinstalled everything and it works SO much better. Throttle response around 30% throttle isn't as crisp as I would like, but it's not very bothersome. Other than than running fine.