Electrical smoke from under seat

[TurnerBFC]

Never had any issues in the last 3 years... went out today and smelt something smoking. Tried to start and no power. Took off seat and smoke was coming out.... now I know everyone will say vts... but it’s been disconnected for the last 3 years!! Traced to the 5A mpem fuse blew. Replaced it and I get it alive again but it’s ‘finnicky’. Ski then started and we shut it off after 10 seconds and the 5A fuse was changing color as if it was just about to blow because it was getting hot. I haven’t touched it since because I’m not sure where to start but the only thing that happened last weekend before this started was it was under water up to the battery (friend flipped it). I should also add that when it did start after replacing 5A fuse... the battery light was on!

Any inputs where to look or start? I’m thinking battery could be fried or maybe a short to ground, stator, rectifier?

 

[AKnarrowback]

Did you smell the burnt smell after running the starter, or trying to run the starter. There are a lot if amps being dumped into the starter and if it is locked up and burning up inside it is going to make some smell. However, it should be sealed up and not releasing a enough smoke, in a short time, to fill the hull area.

Just a thought, it does sound like you are dealing with another problem.

 

[POPPS]

Seems like a short, or, it's possible, that the starter selenoid is sticking,..staying on...

 

[Ckrawiec]

Never had any issues in the last 3 years... went out today and smelt something smoking. Tried to start and no power. Took off seat and smoke was coming out.... now I know everyone will say vts... but it’s been disconnected for the last 3 years!! Traced to the 5A mpem fuse blew. Replaced it and I get it alive again but it’s ‘finnicky’. Ski then started and we shut it off after 10 seconds and the 5A fuse was changing color as if it was just about to blow because it was getting hot. I haven’t touched it since because I’m not sure where to start but the only thing that happened last weekend before this started was it was under water up to the battery (friend flipped it). I should also add that when it did start after replacing 5A fuse... the battery light was on!

Any inputs where to look or start? I’m thinking battery could be fried or maybe a short to ground, stator, rectifier?

First off, letting the smoke out of electrical components is NEVER a good thing.....smoke is a vital part of the electrical system (joking, of course but I learned that from an old Elec Tech...he always thought it humorous to say). Blown fuse = overvoltage.
My initial guess is the rectifier is putting out excessive DC voltage back to the mpem. With ski running, pull red wire from Rectifier and measure DC voltage coming out of the rectifier...should be 13.5 to 14.5 VDC (thereabout), anything higher would indicate a rectifier problem potentially.

 

[mikidymac]

Years ago, at a race, on the back stretch, that 5 amp fuse went, the engine just shut down , i thot it was just another seizure, but there were no electrics at all. , I believe it protects the selenoid, I replaced the slowly failing selenoid and solved that issue. since we run msd anyway, I got rid of the mpem, which you can't do.

And, just,recently I had a 785 DI, the starter would not turn off, and the negative on the battery post melted off like solder...selenoid stuck, replaced the selenoid, and issue solved, these comments are just based on my experiences.

Good info. I have seen a lot of the cheap aftermarket solenoids fail like this.

Also I assume 787 RFI as the DI is a 951 or your a mad scientist, lol.

 

[POPPS]

Apologies, just senile , 785 indirect injection...If you put the lanyard on.get 2 beep beeps, and take a Bettery pack, place the positive to positive of the starter, and take the negative of the booster pack, to the battery, or engine ground, does the starter engage, and the motor runs?

 

[mikidymac]

Apologies, just senile , 785 indirect injection...If you put the lanyard on.get 2 beep beeps, and take a Bettery pack, place the positive to positive of the starter, and take the negative of the booster pack, to the battery, or engine ground, does the starter engage, and the motor runs?

Hold ON! Never put a booster pack on a Seadoo ever or you risk blowing the MPEM.
If you have to test something with battery voltage use jumper cables and a standard 12V battery.