1993 Sea-Doo SPX : Could use some help pinpointing the problem - (video)

[chaos67731]

So I was given this old Sea-Doo, and am trying to get it running. I have cleaned out the old gas, cleaned the carburetor, put new spark plugs in it and got a new battery.

Now when I go to start it, it sounds like the starter is bad but I am not 100% sure. I have taken a video to better show what is going on.

I try "starting" it 4 different ways.

1: Spark plugs out and pushing the button
2: Spark plugs out and bypassing starter solenoid wiring
3: Spark plugs in and pushing the button
4: Spark plugs in and bypassing starter solenoid wiring

With #2 the rods move but with #4 they do not move, I am not sure if that is normal but I do not think it is.
With #1 and #3, nothing but what I think is the starter just turns.

Any pointers would be great, and thanks in advance for the help.

[video=youtube_share;0vQKEnQoQKU]https://youtu.be/0vQKEnQoQKU[/video]

 

[Triorieel]

There is not enough energy to fight the compression; not even enough to start with the plugs in. Even though it is a new battery are you sure it is fully charged?

Note:
To my understanding, the spark plug wires are supposed to be grounded when you do this. I usually leave the spark plugs in and use a small jump wire to ground.

 

[chaos67731]

I thought it might be a bad battery as well. So I hooked it up to my truck (2500 Avalanche) well it was running and the same thing happens.

 

[Triorieel]

I would verify the connections and wires are good, then I would be looking at the starter further.

From my limited view point:

The solenoid not fully engaging typically means bad contact or weak power. But this only answers #1 and #3, not #4.
The fact you have tried your truck battery, I would say weak battery power shouldn't be on the list anymore. Once you verify cables and power connections as ok, I would treat #1 and #3 as a separate symptom to #4.

1 thing to try for a weak connection, run your step 4 while monitoring the voltage on the battery, notice how much the voltage dips. THEN monitor the voltage dip at the starter rerunning step 4. If the voltage dip is noticeably different, then you know it is somewhere in the wiring/connections.


break down:
Starter turns engine.

if starter cant turn engine, then it isn't strong enough.

This would mean starter doesn't have enough energy(battery, bad connections etc...)
Starter is weak (coils bridged, etc...)
or engine has to much resistance.





Also, I keep reading the seadoo computers are sensitive to voltage. I wouldn't hook it up to a running vehicle as that might be outputting voltage higher then the computers design.


I am new to seadoo's, this would be more of how I would break it down with a car.

 

[chaos67731]

I hooked the spark plugs to the ground well they were out but plugged in and I was trying to start it. I did not see a spark, so I am guessing there might be a wiring problem?

Thanks for the help, I will check out the voltage and see if there are any drops well also looking at the wiring and connection points.

I guess I should also find a wiring diagram for the box with the starter solenoid.

This thing was given to me by a guy that said it was sitting for about 3 years, so there is no telling what could be wrong with it.

 

[vogs77]

I just rebuilt the starter on mine because it would not crank with the plugs in, might want to try that first. Cheep ebay kit worked great.

 

[Iceman2017]

I thought it might be a bad battery as well. So I hooked it up to my truck (2500 Avalanche) well it was running and the same thing happens.

You could have fried the MPEM electronics when jumping it from your truck...I'm not an expert but I have always been told NEVER jump the seadoo...and only recharge the battery after first disconnecting everything from the battery.

 

[chaos67731]

You could have fried the MPEM electronics when jumping it from your truck...I'm not an expert but I have always been told NEVER jump the seadoo...and only recharge the battery after first disconnecting everything from the battery.

I am guessing that might of happened, after working on it for a little bit I was able to get it to try and turn over when pushing the start button. Well it did not start, I was super happy that the motor was turning
with just pushing the start button.

That happiness only lasted about 2 seconds. . . . when I released the start button, it would not stop trying to turn over and some wires going from the MPEM to the little box next to the motor got hot and started to smoke.

Now when I push the button, it just keeps trying to start and the wires smoke and turn red. I have to disconnect the battery to get it to stop.

I think I might need new wiring and MPEM at this point.

 

[mikidymac]

Yes. Having a running vehicle jumping it will typically fry the computer (MPEM). Too many amps.

 

[Triorieel]

Wires getting hot means too much current for that electrical pathway. If it's just a section of wire, then it might be pinched or a bad connection at that location, if it's the whole wire...then some serious current is going through (maybe even shorted).

I guess the first and probably easiest thing to do is test the start button. there is probably a disconnect somewhere, I would disconnect it, put your ohm meter on the switch side and make sure while you press the button and release it, you see the resistance going open and closed (infinite to roughly 0 ohm's). Make sure you use that button during that test the same way you do when you start it. Try a bit different angles etc... You are looking for a problem, not to see if it can work.

I would then check the solenoid in the electrical box. Use your volt meter/ohm meter and make sure it properly opens and closes. When you go to start it and it stays closed, is it because the mpem is still giving power to do so? (volt meter on the trigger side will tell you).

If this was a car, I would remove the starter, hold it down tight and give it direct power to see how it turns. Keep in mind the holding it down as starters are torque-y little things that will jump out of your hands. You said the wires smoked in 2 seconds. If the starter runs for 5-10seconds and no warm wires...I would weight it lower as the problem and move on. If they are warm, as a last shot, It might be able to get disassembled and look for any debris inside the starter motor that could cause a short. or maybe it's heavily corroded inside and has high mechanical resistance that just needs cleaned and probably greased (again, car knowledge). If you don't see any problems, you probably are looking at a new starter.

After that, try to break down the electrical connection from the starter all the way to the battery, if you are left with the mpem that is in the middle, you regretfully are probably looking at an mpem replacement.


Disclaimer: But this is speculation from me, who is new to seadoos, has never had this problem, and doesn't know your doo.