Electrical questions

[Jetjon24]

Hello! A while back I gave up on my 1998 gtx ltd jet Jon project and posted it on Craigslist, but before it sold, a friend came by and helped me figure out my problem was just a starter motor. I got it running and took it out twice and it was amazing! But the second time I took it out, after it stalled (I’m still figuring out carb adjustments), I got the dreaded clicking noise from the starter relay and no crank (so I paddled home). I then sanded all my grounds and connections and toyed around with the relay. I now have crank, but no spark. I charged my battery fully and still no spark. My guess was that since it is cranking, my relay is fine and I probably fried my ignition coil. There was a considerable amount of water in the boat because my running bilge pumps were actually pumping water into the boat as the engine ran. If I have a solid crank but no spark and have checked every connection and ground, do you think my problem is either ignition coils or starter relay? If not, what could it be and how can I test it? Thanks in advance!

 

[Chester]

Check your cranking voltage. If it drops below 10.3 volts, it'll crank properly but not spark.

Chester

 

[Steve762us]

I don't know if this will apply to your 1998 ski...but--

On my 1996 Challenger, there are 'ground posts' for
the spark plug leads. If you want to crank engine without
starting it (guessing you might have done that, troubleshooting
/replacing the starter), the plug leads are supposed to be on
the ground posts.

If the engine's cranked with detached, ungrounded spark leads
---in some model years---it blows a fuse in the MPEM box, and
you can crank till cows come home afterward, and she won't
start, till that fuse is replaced.

My boat was missing the ground posts when I got it (and I
wouldn't have known what they were for, anyway). I popped
the fuse a couple of times, until I read one of the obscure
Seadoo service bulletins that covered the phenomenon.

 

[Jetjon24]

Thanks for your responses! My battery cranked 10.6v w/o being charged and then cranked 12.1v with a jumper battery. My only bad fuse was the VTS fuse (my vts motor is trashed and I created fixed brackets for my trim and unplugged all vts wires a long time ago), even so, I replaced the vts fuse and still no spark. I tested ohms for all my wires and read no ohms on anything accept for testing spark plug cap to spark plug cap where I read 22.36 Killo-Ohms (my meter said 22.36Ku). Does this mean my ignition coil is shot?

 

[Jetjon24]

I just looked at my manual again and it said that i needed to remove the plug caps before testing the secondary coil. I did that and got 12.12 Kilo Ohms, which is in the proper range (8.4-15.6). What else could my problem be? MPED? Starter solenoid?

 

[Steve762us]

If it cranks over, the start solenoid is ok...

 

[etemplet]

I had this problem on my first GTX. Debris on the pick up for the rotor position prevented it from detecting the passage of the magnet (or whatever it is... ) ... so the ski would not fire. This situation cannot be found by external testing of the pick up. I ended up chasing the CDI and holder relay for the problem. You have to remove the front engine mount and pull the mag cover. The part is "right there" in the cover. Good Luck !!

 

[Jetjon24]

I never would've thought to check that... The way my boat is set up, I'm probably going to need to pull the engine to get at that, so I will get around to it over Christmas break and I'll let you know what I find. Thanks so much for the help!

 

[etemplet]

I'd do more checking on that ignition coil and wiring before I pulled the mag cover. With the 787 engine in the GTX it isn't all that bad a job to pull the stator cover but is sure isn't any fun. Seems kinda odd that, that pick up would have problems all of a sudden and coincidentally the same time you get a no crank. Hmmmm.... Keep that pick up in the back of your mind and check other stuff. the pick up is on the top right in the picture. I had corrosion so I cleaned the housing and painted it with Glyptol. You don't have to go that far overboard.... LOL

 

[etemplet]

Also.... I'm sure you removed and replaced the key a few times as you're checking for spark. I dunno what it is but sometimes I get a no spark, replace and wiggle the key and it fires right up. It's not for lack of looking around and checking though.

 

[Jetjon24]

Is that same issue common with the 951 engine? It would make sense because I recently had a starter motor that ground out and there probably are still metal flakes in there somewhere.

 

[etemplet]

My issue was that at some point water or moisture was able to get into the chamber and begin the corrosion process. I"m sure metal particles and debris fome gear mesh and friction over time could become a problem as well. I just cleaned mine up the best I could, replaced the pickup that wasn't bad and that was that. Fired right on up after that. That problem was not an easy find for me as this was my first GTX. The guy I bought the ski from (not running, but running sometimes) was a Mercedes mechanic and so were his 2 buddies. They couldn't get it fixed either.

How are you checking for fire? I use a handy dandy little clear plastic tube from the auto parts store with connections on each end. You plug it inline with the spark plug and you can see easily if you are getting spark. Good Luck !!

 

[Jetjon24]

I just check spark by grounding it against metal and cranking. Maybe it’s not the best way, but I used to be able to see spark when doing it and now I can’t

 

[etemplet]

I just check spark by grounding it against metal and cranking. Maybe it’s not the best way, but I used to be able to see spark when doing it and now I can’t

I can't argue with that. I did it that way for 40 years. LOL For around 5 bucks you can get a cool tool and the ski will run while it is connected so you can check for loss of spark while it is running. I keep it in my tool box and nearby.

I am also a candy azz when it comes to potentially getting electrified myself. This tool is "hands free."

 

[Jetjon24]

So I finally got a chance to take apart the engine, and it was a lot cleaner than I imagined. I didn’t find any corrosion on the pickups and the stator looks clean. I’m attatching pics of the stator/pickups, but it all looked good to me. Any idea what else would cause me to loose spark?

 

[etemplet]

That does look pretty clean. Did you check the resistance on the wires coming from the stator and the puck up? Did you do resistance checks on the MPEM ?

 

[Jetjon24]

I have done testing with the stator. I have not done MPEM testing, but I’ll do that next. It should be easier now that everything is apart. I still have my suspicions that it’s just grounds, because I have had that issue before, but I definitely need to test everything while I can before putting it back together and sanding grounds.

 

[etemplet]

Try to identify the correct wires and test them. I had trouble with my 96 GTX not recognizing the key insertion. Then all of a sudden it would work fine. Matt Braley suggested I clean the wire connections. I bought the tool so I could pull the pins. First thing I found was on the Dess connection plug. It had dirt internally on one of the plugs, only on one wire (black wire I think and that would be the ground). I'd always get voltage when I tested it. I even replaced the Dess post. It tricked me a few times into thinking it was fixed. LOL Check those connections !! Buy the tool so you can take them apart.

I still have some trepidation when inserting the key in the Dess now but so far it is 100% good !! YAY

THANKS MATT !!

 

[Jetjon24]

Today I used my volt meter to test how many volt are getting to the ignition coils (I did this by holding one probe to coil and one to the negative terminal on the battery). It had 0v, then when I cranked it jumped up to roughly 12v, so I assume that everything up until the coil works, and my coil is bad. So I’m going to get new coils, and hopefully that fixes it.

 

[Jetjon24]

Well... I installed the new ignition coil and still have no spark. Now I'm only reading like 0.3v dc getting to the coil. I could've sworn I measured around 11-12v dc getting to the coil before i bought the new one. I guess the next step is testing the mpem according to manual specs. Are there any parts other than the MPEM that could allow it to crank but not spark (other than the ignition coil which i replaced) or are there any wires that if not connected will allow crank but not spark?

 

[etemplet]

Since you had power previously it should be something simple... hopefully. Fuses, solenoid wiring, good ground. Electrical issues irk me. I defer back to a Millwright Foreman I met a long time ago, He said, "3 things I know about electricity. You can't see it, It bites, and I ain't F'n with it !" Of course he was referring to high powered electrical equipment but all three still apply.

 

[Jetjon24]

"You can't see it, it bites, and I ain't messin with it" thats how I feel about the ski right now... The ski has gone from not spark to no crank. I've checked what feels like every ground, connection, and wire and everything seems right. Does this sound like a dying MPEM? Do MPEMs ever just stop working or slowly decay like this? That's the only thing i can think of at this point unless I have something that's not plugged in right or something. thanks in advance

 

[etemplet]

Bypass the solenoid to check the starter again. You checked all your fuses. Keep it simple till the problem is not simple. Not sure what all you checked but the Dess Post and Starter switch need to be verified. Stick with it !!