seadoo gt 580 no spark

[frederick]

hi ive got a seadoo gt 580cc with no spark.
havnt tried anything yet but wondered if there were any checks I could do to iliminate things before getting to involved.
gona get some replacement plug caps and refit by cutting 1/2inch or so off end of old lead 2morra but any advice on other common faults would be appreiciated.
cheers fred

 

[- BiRkS_]

Check the fuses in the grey electrical box, unplug the Rev limiter also and see if you get spark.

To get a wiring diagram, download the shop manual. www DOT seadoomanuals DOT net

 

[frederick]

cheers will do that and see what happens (just got ski and it needed starter motor) after I fitted one it appeared to have faint spark but then it went so hopefully will be something silly.

 

[jhjesse]

Unscrew the spark plug wire caps and trim the plug wires back about 1/4 of an inch. Reinstall the caps and try.

Good luck!

 

[frederick]

bought 2 new caps cant unscew old ones so will cut them off and fit new ones thisafta and keep me fingers crossed.
thanks for reply.

 

[frederick]

Hi ive fitted new plug caps and checked both fuses (both ok)
what does the rev limiter look like and is it located in the grey box
cheers fred

 

[frederick]

Hi ive fitted new plug caps and checked both fuses (both ok) still no spark.
what does the rev limiter look like and is it located in the grey box
cheers fred

 

[68ragtop]

what year is this ski? assuming its at least a 1992, there should be module in your electronic box that has about 8 wires coming out of it. Look for a black with red stripe that connects to one side of the coil. The wire is your rev limiter & engine shit off control. Unplug that wire & see if you have spark. IF you try to start the ski, be warned you will have no way to shut it off, other than giving it full choke.

Also, while checking, keep in mind that you have to check both spark plugs at the same time, or make sure one is wire is grounded. If one spark plug wire is laying loose, you will have no spark on an otherwise perfectly working system.

Like mentioned above, you might just be lacking power to the MPEM module, but this is an easy test to see if your ignition system is working, then move forward from there.

 

[frederick]

your an angel and im a PUDDING.
ive just done what you said and grounded second lead and bingo ive got a spark.
when I think about it that's probably why there was a spark in first instance (meby second plug was still screwed in head)
I must have had what we call a senior moment. ha ha
anyway thank you very much for your information its much appreiciated cheers fred

 

[frederick]

hi folks im back with my problems ski is a 1990 seadoo gt with an orangy yellow engine (pretty sure its a 580cc) as before my problem is a sparking issue.
if I take both plugs out and ground both at bottom end I get either no spark or almost none.
however if I ground either plug from top end (by shoving a ground wire in with plug cap) I get a brilliant spark on either plug.
ive changed plug caps and coil and cdi and also cleaned the magnets in the flywheel.
is there anything left exept the magneto
also can anyone tell me what sort of voltage I should have from magneto to cdi also is it a big job to change magneto please.
also will a magneto from a seadoo 720 gti fit the earlier 580 seadoo (looks similar and wires are same colours) cheers freed

 

[Minnetonka4me]

Heres what you need to do. Open up the top of the ebox and theres a small module hiding in the bottom of it. Theres a red or blk/red coming out of it. Disconnect it then retry. It will disable the revlimit and kill switches to be aware of that.

If you get spark its that module, very common issue on the old yellow motor skis.

 

[frederick]

cheers for info. I did as instructed and found I had spark. reconnected everything and STILL had a good spark on both plugs.
so now I have 140psi on both pots. a good spark on both plugs. not sure about fuel so sprayed some EASY START into both pots and the bloody thing still wont fire (not even a splutter)
anyone got any ideas (I always thought if there was spark fuel and compression it should fire)
cheers fred

 

[LouDoo]

About the only other thing is could be is timing, here's a video from SBT showing how to set the timing.

http://www.youtube.com/watch?v=ULL5gfQs_UA

Lou

 

[Minnetonka4me]

There's a few things it could be then. If it had the wrong flywheel that would do it but I'm sure it hasn't been changed. So then a broken key on the flywheel or the rotary valve gear stripped. You could put something flexible into the carb and feel for it rotating correctly. Did it run when you bought it?

Sent from my SGH-T989 using Tapatalk

 

[frederick]

was told it needed starter motor, and had been stood a while otherwise was supposed to have been ok before being laid up.
I am pretty sure carb will need cleaning but before doing anymore I was hopeing to get it to fire up even for a few seconds with easy start rather than mess on with carbs then find it still wont fire.
ive had flywheel off to clean magnets and woodruff key was ok and timing marks lined up at TDC.
cant understand why with good compression and spark that it will not fire with easy start in pots. I am starting to thing best thing might be to sell as is or break for spares but don't want to let it get the better of me (if you know what I mean)

 

[LouDoo]

From what you're saying it's sounding like your rotary valve gear is worn or stripped. If you watched the SBT video you can see how it works.

http://www.youtube.com/watch?v=ULL5gfQs_UA

So if the rotary valve is either not turning or out of time you won't get fuel or air into the engine. The easiest way to check if the rotary valve is turning is use a borescope, if you don't have one you can try a piece of small tuning, if you still can't tell you will need to remove a carb. and visually check. If the rotary valve is not turning you will need to replace the rotary valve gear.

http://fiche.seadoowarehouse.com/se...d=-ROTARY-VALVE-ASSY.-W/-COOLING-SYSTEM-INLET

Since I have never replaced one on a 580, I will let someone else, like Nick advise you on how to change the gear, I think you will need to split the case.

BTW, one of the oldest lies when buying a used SeaDoo is "all it needs is a starter". Because the buyer can't check to see if the PWC starts or even if it has compression.

Good luck,

Lou

 

[frederick]

cheers for info lou im retied and just bought ski to mess around with only paid £200 for it so may just sell as is or split for spares. its on a roller coaster trailer so should easy get my money back as ive never split an engine before so sounds a bit doughnting to me.
might pull carbs off and see if there is anything obvious . I watched video so shouldn't be to much of a problem removing carbs.
either that or I could remove starter motor and advertise as JUST NEEDS STARTER ha ha (wouldn't do that by the way)
cheers for your info and keep skiing (im 70 and still get out) fred

 

[Minnetonka4me]

Welcome to Flipping Seadoos 101

1. When the ad says "needs a starter" it means everything else is complete junk. Sometimes even the starter too.


I think its the RV then...again if it has the correct flywheel. I've put the wrong flywheel on before. spark, no pop.

 

[frederick]

cheers for all replys I am gona put it back together (flywheel cover back on ext) cover it up in the corner till all this snow that's forcast has gone. then see how energetic I feel and either sell as is or have another go.
so merry xmas to you all and hope santa brings you a load of jetski goodies
cheers fred