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  1. #1

    How to tell what model, and electrical problem, no spark tested a few things.....

    Well I picked up my very first watercraft EVER a few days ago. So I'm a total newb when it comes to anything that does not have wheels on it .
    Picked up what I was told is a 95 SL780. However I have no way to varify this.. and was wondering if there is a way to find out, since I'm trying to find electrical parts and want to make sure I'm actually looking for correct parts. I have the 12 digit vin tag if that helps any.

    Now on to the problem at hand. Picked up the unit very cheap, due to its non running state. The engine is totally rebuilt and looks to have zero run time on it. Someone has hacked their way through this thing over the years though. The electrical box was just laying inside, several sets of wires lead to nothing. two of the spark plug boots are torn off, and I think the oil injection system has been removed.

    I managed to look at the wiring diagrams for a 95 SLX780 and it seems to match up from what I can tell. Traced the unknown wires to be the low oil sensor (blue and black) and low fuel sensor (pink and black) The pink and black have been twisted together to bypass the limp mode I assume?

    I went through and attempted to test the stator, kill switch, and coils per some instructions I found on here, my results were mixed.

    Kill switch seems good, open when at rest, closed circuit when pushed (connected to ground)

    Coils seem good, testing each coil seperate I get .6 ohms, testing all three in series I get 1.2 ohms.

    Testing the stator I got one questionable result, it depends what setting my DMM is set to.
    Magneto stator coils
    Red/Purple to Yellow: 0.6 ohms (Alternator coil - battery charging)
    Red/Purple or Yellow to Black: Infinite/open/no connection
    White/Yellow to Black: 220 ohms (Trigger coil)
    Blue/Red to Red/White: 90 ohms (Pulser coil)
    Red/White to Black: Infinite/open/no connection
    Red/White to Green/Red: 490 ohms (Exciter coil)

    All of those tested good besides the on in red. I could get a closed circuit depending on where I set my meter too, only noticed it because I got a split second reading when testing on the 200 ohm setting, thought it was weird so I tried some of the higher settings on the meter also. Just a very fast reading then acts like an open circuit.

    I also noticed the RED/Purple wire coming off the CDI did not go to the matching junction block connector on board in the electrical box, it was connected to a yellow terminal barrier, which I though was odd. So I removed it and pushed it onto an empty tab on thre Red/Purple barrier. I can provide pics later if it may help.

    After testing all of this, hook up a battery, and connecting the single in tact spark plug boot to the plug and resting it on the bare metal of the head, no spark.

    So in theory it looks like my CDI or stator (less likely) is bad, but these are rather expensive theories to just start throwing money at.


    The CDI box I have has more wires coming out of it than most of them I see on ebay, it has a long gray wire and a long light tan wire if I recall correctly, along with the other shorter wires that are common to the other cdi boxes I've come across. Only mentioned this because I have a spare CDI box from another ski from a bone yard that came with the ski, but it does not have these two extra wires (that I have no idea what the are for)


  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    How about a pic of it and the engine?

    You can tell from the HIN number too, but a quick pic will be easier.

  3. #3
    Ok I FINALLY found a Polaris watercraft dealer in my area, and found out by the HIN, that it's a 95 SLT780

    Now on to trying to find my source of no spark. Also think I figured out that the two extra wires in question on the CDI are for the temp sensor beep, and the timing retard for limp mode. That being said I'm going to try a spare CDI I have from another craft that does not have those two wires.

    If the CDI proves to be bad, I wonder where I'm going to find a new one, as they seem to be discontinued

  4. #4
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Quote Originally Posted by Deadly_Evolution View Post
    Ok I FINALLY found a Polaris watercraft dealer in my area, and found out by the HIN, that it's a 95 SLT780

    Now on to trying to find my source of no spark. Also think I figured out that the two extra wires in question on the CDI are for the temp sensor beep, and the timing retard for limp mode. That being said I'm going to try a spare CDI I have from another craft that does not have those two wires.

    If the CDI proves to be bad, I wonder where I'm going to find a new one, as they seem to be discontinued
    Sorry to say there was no 95 SLT 780.

    There was a 95 SLT 750 (3 seater and teal/white in color)

    And a 95 SLX 780 (2 seater and white/red in color)

    Posting pics will help us be able to better guide you.

  5. #5
    Ha yes I mean SLX780 not sure where I got SLT in my typing. It's red, white and black, purple stablizers.

    Eh man I got myself into a can of worms here. CDI is bad, trim motor is bad, fuel pump sender has been jumped, and a few other things, bummer.

  6. #6
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    CDI, nothing you can do.....

    Trim motor can often be freed up. (normally rusted. If you break the rust bond it often comes back to life)

    Fuel sender jumped? (you mean the wires were bypassed? (no biggie if so)

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