98 GTX RFI rectifier/stator troubleshooting sanity check

[elprup]

Hi. Summary: 12v low on display...won't start in water...started on trailer then backed into water...kind of ran, but not to standard max rpms. Compression is fine at ~145. Okay, so, checked fuses in rear electrical box. One 20amp was okay, the other 20amp was blown, the third fuse was fine but was a 3amp (it's really supposed to be a 1amp, right?) The 5amp fuse up front at MPEM is okay.

Back to the rear box...went to replace the blown 20amp fuse and it sparked at me. I stopped, then tried again and it sparked again and then immediately blew the new fuse before I could even press it in. I unplugged the two rectifier wiring harnesses and tried replacing the fuse again. It did not spark or blow this time. By the way, all of this is with the engine off (with no attempts to start). Anyway, I did NOT plug the rectifier back in because I didn't want to move from the fool-me-once stage to the fool-me-twice stage.

At this point, I tested the three yellow wiring harness (one of the two harnesses that the rectifier would be plugged into) for continuity to ground. I tested to the spark plug grounding posts and got the continuity beep. This means the stator is shorted to ground and the mag cover has to come off to deal with it, right?

 

[etemplet]

From Memory the 3 yellow wires resistance should be .3 to .7 ohms or there about. None of the yellow wires should have continuity with ground. You could have a problem with the plug or corrosion in the plug. It is difficult to test those wires inside the plug without a test plug. I have fought those. You'll have to remove the front motor mount. Good Luck.

 

[elprup]

I was testing the three yellow wires back where the rectifier plugs into them, not up at the stator cover.

Yeah, I knew about the motor mount. It's unfortunate the bracket is part of the stator cover, but alas, that was the best place to put it.

 

[etemplet]

The place where you tested doesn't prove the stater is bad. You could have some bad wiring or Corrosion at the plug. Just saying testing there doesn't rule out other issues. One thing good is the stator is in the cover and not behind the flywheel. Be careful loosening the bolts on the cover. I've had problems on a few but I work on some salt water skis. Good Luck.

 

[elprup]

Whoever was in this before me couldn't bring themselves to loosen two bolts in order to properly run the stator wiring harness under the bracket. The trigger wheel likes to rub on the wires when the wiring harness isn't behind the bracket.

This is pretty bad, but it's not even the best part. The oil pump shaft...yeah, it wasn't even in there! So, nothing was turning the oil pump. Good thing the wiring issue happened because this engine would've been toast. If I didn't have a reason to pull the stator cover, the missing oil pump shaft would've been an eternal mystery as to why this engine would have kept failing.

Sometime later I'll post a picture of the mini engine hoist I "built."

 

[etemplet]

Welcome to the world of Seadoo. WOW !! Not sure which pump drive coupling is on the parts list but from what I understand the old style is less reliable than the one that is driven by the flywheel nut. Do some checking. I just reuse what was in there most of the time as long as it is in good condition. Good Luck !!

 

[elprup]

The RFI's use the black one that goes on the flywheel nut.

 

[elprup]

Buttoned back up (and now the plastic oil pump shaft is no longer MIA...still can't believe that!). Tested the rectifier and the battery voltage only went down on rpm increase, so it's not functioning. Rechecked the 20amp fuse in the rear black box and it was blown again. The three yellow stator wires no longer have continuity to ground and ohm between .3 - .9 (I think that's okay because isn't something like 1 the max?). I tested the red wire from the rectifier for continuity to battery positive and got no continuity. Replaced the blown 20amp fuse and the red rectifier wire still had no continuity to battery positive.

After addressing the stator wiring issue, I've reached the point where the rectifier needs replaced, right? Oh, the three yellow rectifier wires ohm at 3.1 among them, but the fact that's there is no continuity from rectifier red to battery positive means the rectifier needs replaced, correct?

 

[etemplet]

I never checked red wire continuity that way and since the rectifer is solid state we don't know what they are doing inside. Could be the rectifier blowing the fuse as I had a bad rectifer on a 1996 SPI and it blew the Diode in the Mpem. Do you have Continuity between the (red) and any ground? Rectifer's are cheap anyway... go for it. You don't need that super duper $100 one either. Less than $30 is just fine. Get the one that plugs right into your ski. Good Luck !!

 

[elprup]

Well, another stupid problem solved... Had you not posted your rectifier recommendation, I would've used the buy-once-cry-once method on the $100 one. First, I picked a cheap one out on ebay. Then, I went and checked Amazon. I read some reviews that mentioned the red and green wires were reversed. As you can imagine, this prompted me to go check the one that was in there and sure enough, they were switched in the harness (it wasn't the original rectifier). Switched the wires on the rectifier harness so that red was going to red and green was going to black. Started the engine, and it maxed at about 13.5 volts at 5500rpm. Yeah!

 

[elprup]

I don't know how people are managing to put pieces of wood under the engine. I determined it was going to be an exercise in futility, so I put on my thinking cap and came up with this. You wrap a strap around the front of the engine and then tie the ends together. Make sure to go between the engine block and starter instead of around the starter. Then, use a ratchet strap around a vertical 2x4 and you have yourself a mini, temporary engine hoist. Strap lengths are different on different ratchet straps, so in my instance, I had to use a wrench in order to give the hook something to grab (because that's where it needed to grab something). It's an elongated wrench from Harbor Freight...15/16, I believe, if you wanted to copy this method exactly. Then, when it comes time to get the motor mount out from under the stator cover, you likely will need a partner so you can put a little pressure (pushing toward the back of the PWC) on the 2x4 just enough so the motor mount can be slid out from under the stator cover.

 

[etemplet]

Man that's news to me. I'll have to remember that. Teamwork !! LOL

Blown fuses..check ground. Good Job !! Now ride it like ya stole it !!

 

[elprup]

Man that's news to me. I'll have to remember that. Teamwork !! LOL

Blown fuses..check ground. Good Job !! Now ride it like ya stole it !!

Yeah, when doing all this research I never came across that as a possibility...I had to discover it from a few reviews on Amazon; go figure.

 

[etemplet]

Block of wood under the engine is quick and easy. Remove the mount, lift the front of the engine with one hand while positioning the block with the other. You're just getting the mount out of the way and holding the engine roughly in poistion. It's quick and easy. To each his own, whatever works for you.r. Good Job !

 

[elprup]

I also found out that putting the plastic oil pump shaft on the trigger wheel nut before lowering the stator cover down into position doesn't work well. I knocked it off three times! So, maybe that's what happened to the previous person that was in this engine. Well, I heard it fall all three times so whomever that person was needs to get their hearing checked if that's what happened. Anyway, on the fourth attempt, I positioned the stator cover then moved it back just enough to squeeze the oil pump shaft into place. You have to be careful when doing this because the oil lines are stretched to their max at that point. If you get too forceful, you're going to have a bad day with the oil lines. After I got the stator cover in place with a couple of bolts, I used a flashlight and mirror to make sure the oil pump shaft was truly there before bolting the oil pump back on.

 

[etemplet]

I can't hear for shit so... it's not by choice. LOL

 

[hypoxia]

Awesome to see a thread dated in 2021. I actually picked up an RFI ski that keeps killing batteries. I put in a new fresh battery, tested 13v at idle and called it good. I went out yesterday got a 12v low and it was dead the next time I went to start it.

This is good info. Sometimes these simple stator/rectifer/battery issues are a little bit more in depth than they should be and whoever reading this should take all the proper steps when troubleshooting.