Rebuilt GSX Ltd - no spark

[CraigG]

Hi Folks,

New here, and have recently, rather stupidly.... blindly rebuilt a 951 engine for a GSX Limited. I had picked up 2 ski's both dead, and made 1 good one out of the pair.

Got the engine reassembled, and everything in and plumbed in, but no spark. upon investigation, it appears that despite both ski's being "the same" (red/purple) the MPEM units have different part numbers, I am thinking this is where my issue lies.

The one fitted (the only one with a key) is marked up 98M1330-A / 071000-1330. the other unit I have, has part numbers 278001558 / 071000-1332. I cant find reference to these part numbers on any of the online parts catalogues, so unsure what that is about. But I suspect my issue is relating to the signal from the magneto, as I understand from reading that they changed from 2 to 4 trigger magnets at some point in 97/98 ? both ski's had identical wiring looms and electrical boxes (single coil). So at the time I didn't even consider there would be other differences. I just fitted the MPEM that I had the key for, and the engine was rebuilt with the best of the parts that were there.

Unfortunately, the other engine is long gone, so I cant get/check the magneto off that. but before I tear down the front of it to check, I am wondering if someone can tell me what magneto (2 or 4?) should be going with the MPEM I have fitted?

Or am I getting ahead of myself and there is something else I have not considered? Ski gives me 2 short beeps when I attach the key which supposed to mean everything is a-ok with the DESS? The dash appears to work, it cranks over very well, coil is tested with in-spec resistances in both windings.

any help would be appreciated!

 

[etemplet]

I do a search on "where used" on the two part numbers 71001330 and 71001332. That used to be an easy thing to do on the Seadoo site but it doesn't work as well as it once did.

 

[CraigG]

Those 071 numbers appear to be the Denso part numbers rather than Seadoo's. but that doesnt help much :/

Just unsure as to why the other part numbers don't appear anywhere on Seadoo's catalogues, they are clearly meant to be in these ski's

 

[etemplet]

Oh well, it had the right number of digits. LOL I find it strange you are getting "no spark" at all. I have a 1998 GTX and I've built one previously. The 98' had a specific flywheel that was model specific. Got me wondering if you just need the correct flywheel. I'll look in my parts pile to verify a few items. I'm pretty sure the MPEM is still in the ski so can check that number for you.

 

[CraigG]

I've got a new coil to go in, current one is testing at 22kohm between the leads, so that's a bit out of spec, getting no power from the white wire at the back of the ski, so the coil wont be firing even if it had good resistance, continuity is good from the back to the MPEM plug on the white wire.

It was installed with a new stator/plug, so expect that to be correct.

Think I am going to bit the bullet tonight and pull the exhaust/cover to check the magneto, and its positioning on the flywheel, I had the crank rebuilt, so I didn't actually install the magneto... I guess its possible they have not put it on in the correct orientation in reference to the flywheel?

 

[CraigG]

As mentioned, I get 2 short beeps with the key, and then 1 long beep after ~5seconds or so, but the dash is showing low oil (which it is) so I assume that's what the long beep is about?

 

[etemplet]

Been a while for me with the carb 951, does it have a pick up like the 787 mounted in the cover? (magnet type?)

 

[CraigG]

Yea pickup in the cover, magneto and flywheel so appear to be aligned, it's a 2 magnet magneto, which I suspect is correct for the age

Only discrepancy I can see, the 6 pin plug has a black wire from the stator, but no corresponding wire on the loom (checked both looms, it's the same) and the old stator that came out also has a black wire to nowhere, misnomer, or does that need grounded on the loom side?

 

[CraigG]

been tracing all the wires, and everything appears to be connected and have good continuity around the ski, just don't appear to be getting any signal out of the white wire from the MPEM to the coil.

Would the low oil alarm cause it to cut ignition/spark?

 

[mikidymac]

No, low oil, low fuel and temp sensor have nothing to do with the ski running or spark.

 

[CraigG]

wishful thinking on my part!

 

[bultaco]

Make sure you have a good battery Mine loses spark below 12 volts

 

[bultaco]

Mine would crank engine but not provide spark New battery started right up

 

[CraigG]

yea its got a brand new battery fitted, cranks over very strong.

found someone local with Canpro that can code a key, so I am going to try the other MPEM in it, see if that makes any change.

If that doesn't work, then I am at a loss

 

[CraigG]

Still not been able to get the other mpem key coded, is there any way of testing the trigger coil in the mpem that I currently have? Like a resistance check or something?

One thing I have read that is bad, and I have done, is run a motorcycle battery optimiser on the ski, with everything plugged in... Could that have caused this no spark issue?

Still unable to find any correspondence between the denso part number and seadoo, to see if either of the mpem's I have are right

 

[2strokeboy]

The 951 went through a lot of changes over the short amount of years it lived and a lot of these changes were in ignition.

The raised parts on the mag are in different places and the stator is different, mpem coding is different. I think this is most likely your problem. If you can get the other mpem coded I would try that. Otherwise you will have to see if the mag you have is different than the mag that was on it originally.