Seadoo Sportster 717/720 No Spark

[Newbie69]

Hello, recently instally fresh rebuilt motor in my 1996 Sportster 717/720. New everything. No spark. Tested 3 known working Cdi/coils no luck, Replaced stator with brand new one, no luck. Stator checks out with all wire combos being well within spec. The coil trigger wire while cranking is only getting 4.2 dcv. Get 2 beeps while putting key on and it turns over all day long. One thing that did happen was the previous owner rigged up the stereo with a white and yellow wire (negative and positive) and both got put on to the positive on the battery. The fuse block wire #13 melted. I replaced that wire and removed the stereo completely. Am i having a ground issue now ? Does anyone know the mpem test for this boat ? There are mpem tests on here for the 717/720 but I don't have this black/red wire they say to unhook between the coil and mpem to test for spark. Anyone able to help this fella out with a starting point here. Anything would be appreciated!!

 

[rusty nail]

the white wire on the back of the ignition coil is the signal wire that comes "up stream" from there. unplug the white wire and put your test light between the ground and the white wire and crank the motor and light should flash at every spark signal. If not, problem is up stream including all the other things you have tested. Have you checked the 5amp fuse in the mpem? it protects that spark circuit in the mpem. if it is blown try changing it...you might get lucky....however it is very well known that these mpem are sensitive to power surges and diode in the mpem could be damaged. the 5amp fuse will continually blow if this has happened. there are other forums here where some have tried to replace the diode by digging out the potting in the mpem to replace this diode if it is the case.

one other thing you could try is unplugging the rectifier. your boat will not charge the battery if it is the problem but it may keep it from getting spark when cranking.

 

[Newbie69]

the white wire on the back of the ignition coil is the signal wire that comes "up stream" from there. unplug the white wire and put your test light between the ground and the white wire and crank the motor and light should flash at every spark signal. If not, problem is up stream including all the other things you have tested. Have you checked the 5amp fuse in the mpem? it protects that spark circuit in the mpem. if it is blown try changing it...you might get lucky....however it is very well known that these mpem are sensitive to power surges and diode in the mpem could be damaged. the 5amp fuse will continually blow if this has happened. there are other forums here where some have tried to replace the diode by digging out the potting in the mpem to replace this diode if it is the case.

one other thing you could try is unplugging the rectifier. your boat will not charge the battery if it is the problem but it may keep it from getting spark when cranking.

 

[Newbie69]

Them MPEM ended up being toast. Well The Rev Limiter wire. We removed it from the coil and ran a direct wire from the black with red/green stripe wire to the coil itself and had spark. With the rev limiter wire on again we got nothing.