1990 SP 'Craigslist Special' - No Spark....

[Dave_A]

I got this thing for $250 off CL. It needs paint & the graphics are long gone...

Also, the oil tank is gone, so I'm assuming it was converted to premix....

That said, compression is strong, it turns over freely, and I got a sealed AGM battery to replace the dead harley-battery that came with it... I'm assuming the carbs need cleaning but I'll hit that up after I fix the major issue... Which is:

NO SPARK.

Being somewhat familiar with Denso CDIs (and being glad this is a pre-MPEM unit, with separate CDI, rev-limiter, and coil), I've done the following:

1) Checked grounds - when I got it, the brown ground was disconnected inside the flywheel-box, it has now been reconnected

2) Bypassed the entire rev-limiter/stop-switch/lanyard-switch assembly, by connecting the battery-+ wire that goes 'up into' the handlebars, directly to the black wire that comes out of the rev-limiter to power the CDI (fortunately, they snap together w/o any modification).

While I can't run the ski that way, I can diagnose spark that way & re-connect everything after I have a good baseline.

3) Checked connections of all the wires down in the flywheel area.

At this point, there is still no spark.

The ground side of the coil-output from the CDI tests good.

The positive side has no voltage when not cranking, and a small voltage when cranking (measured with a MM connected between coil+ and ground, coming out of the CDI.

I'm thinking bad coil...

Any other ideas?

I presume that because I'm getting juice out of the CDI's coil-driver line when the engine cranks (but none when it doesn't), that the pickups and CDI itself are working.

Am I missing anything, or should I try a spare coil (I've got some 2-output coils from a GS-850 bike, which also uses a Denso CDI - they should work for test purposes)???

Any good guides for CDI testing with a multimeter, as opposed to Seadoo 'special tools'?

 

[Dr Honda]

Did you put voltage on the CDI? If you did... you may have roasted it. The ignition is self contained. THe HV coils in the MAG feed the CDI, and the CDI in turn feeds the coil.

The only thing in that box that needs power (other than the starter) is the "Speed-limiter." (rev-limiter) The speed limiter just grounds the CDI to control the rev's. (or to kill the engine)


But... let's look at 2 more points.....


1) If the oil tank is missing... that's bad. Even if it was converted to Pre-mix... you still need the tank to feed the rotary gears. If they are dry, they won't last long.


2) Compression. You said it's strong... but what is it? That engine should be around 145~150 psi. If it's below 120... it isn't going to run. (at least not well)

 

[Dave_A]

Did you put voltage on the CDI? If you did... you may have roasted it. The ignition is self contained. THe HV coils in the MAG feed the CDI, and the CDI in turn feeds the coil.

The only thing in that box that needs power (other than the starter) is the "Speed-limiter." (rev-limiter) The speed limiter just grounds the CDI to control the rev's. (or to kill the engine)


But... let's look at 2 more points.....


1) If the oil tank is missing... that's bad. Even if it was converted to Pre-mix... you still need the tank to feed the rotary gears. If they are dry, they won't last long.


2) Compression. You said it's strong... but what is it? That engine should be around 145~150 psi. If it's below 120... it isn't going to run. (at least not well)

I didn't connect power straight to the ddi - I connected power to the output wire from the rev limiter, thinking the signal was supposed to be +12v, instead of ground... That said I have a spare known good ddi if I need it....

for the oil, they did the oil filled hose thing to lube the rv gear, a/o the tank. I don't have the old tank either....

 

[brock1]

if you dont have the tank how is the oil being curculated???? did they just rin one hose from each port and cal it good.....

 

[Dave_A]

if you dont have the tank how is the oil being curculated???? did they just rin one hose from each port and cal it good.....

As far as I can tell, yes...

The 'hose-full-of-oil' thing has come up when I googled the subject, too - so I wouldn't be suprised if they did it that way...

 

[Dave_A]

So, back to my original problem....

I've checked the coil and it seems to check out.. Still no spark.

I have the manual, but all of it's ignition testing 'steps' involve this proprietary SeaDoo gadget - I just have a Harbor Freight multimeter...

Is there an article anywhere around here about testing the CDI and the magento-coil, that lists what' supposed to measure what?

 

[Dave_A]

Oh, one more thing...

Since I did it wrong before: How do I bypass the rev-limiter/safety-box so I don't have to worry about any of 'this stuff' for spark-testing?

I now know NOT to feed it 12v... Is leaving it 'open' OK?

Is the wire from the rev-limiter box to the coil supposed to have continuity to ground, or not?

 

[Dave_A]

anyone? still looking for test specs