Confused

[msmoak5]

Hoping someone can give me some insight on a current issue I’m having. I am new to the SEADOO family! I’ve enjoyed the tear down and rebuild too!

I apologize for the lengthy post!

I recently obtained a 1996 Seadoo SPX from a friend of mine. Initially, my friend said it only needed a battery! Lol I knew that wasn’t the case.

heres what I’ve done thus far....
1. New fuel tank (original was broken at the fuel fill hose.) New fuel filter
2. Replaced all fuel lines and all oil lines, including the oil pump.
3. Rebuilt the carbs
4. Rebuilt the Jet pump and installed new wear ring
5. New Battery
6. New Gauges
7. Used OEM MPEM (original was melted around the fuses)
8. Rebuilt the top end (new pistons and rings) Compression on both cylinders is sitting at 115 psi
9. Rebuilt the OEM starter motor with new OEM parts
10. New NGK spark plugs, gapped at approx. .28 -.30

Went to fire the ski up the other day and it fired right up! Sounded good and figured I’d tweak the low idle on the carb a little. Ran the ski with the water hose in the driveway for about 30 minutes. Turned the machine off, and started it again and ran it for another 30 minutes. That’s when I noticed the #3 bold for the top cover was leaking water....went to tighten the bolt and it broke.
Tear- down of the top end commenced again. After getting the bolt extracted and purchasing another OEM bolt, put the ski back together. Went to start it today and I started for like 3 seconds and then shut off. Spent the next few minutes trying to start it. Prior to starting the ski, the battery was showing 12.6 volts. Made several attempts to start until the battery was weak (bad, I know.) Took the battery out and charged it. Attempted to start again, still nothing. Took the plugs out individually to check for spark, which I was getting faint blue/ white sparks on multiple contacts of the plug. The gas is maybe 4 days old within the tank. The oil is also fresh.

I‘m leaning towards faulty ignition coil/ cables. Is there a way to bench test the ignition cable? I’ve already pulled them from the electrical box. Also, is it possible it’s something I am overlooking? Just confused as to why it started and sound great the other day and now it’s not wanting to fire up?

 

[GGuillot]

Rebuilt the top end (new pistons and rings) Compression on both cylinders is sitting at 115 psi

I'd say this is why it won't start, you didn't get it over bored? The new standard bore pistons and rings didn't accomplish anything to bring the compression up. If 115 is accurate, that's really low. 150 is where you want it to be with a new top end, anything below 120-125 you might get it to start on the trailer/hose, but in the water it won't have the compression to idle under load.

 

[mikidymac]

And running it that long out of the water you probably burned up your driveshaft seal.

 

[msmoak5]

I'd say this is why it won't start, you didn't get it over bored? The new standard bore pistons and rings didn't accomplish anything to bring the compression up. If 115 is accurate, that's really low. 150 is where you want it to be with a new top end, anything below 120-125 you might get it to start on the trailer/hose, but in the water it won't have the compression to idle under load.

I ordered the standard pistons and had a machine shop check out the piston sleeves...original factory honing marks were still visible and the guys at the machine shop said the cylinders did not need boring. So your saying I need to get the cylinders bored and purchase bigger pistons too?

 

[mikidymac]

I would check with a different compression gauge before moving forward and not a Harbor Freight one.
If the 115 psi is correct then there is no reason to move forward as it will not run at that low of a number.

 

[msmoak5]

Decided to take the magneto system apart and check it out...a good bit of dust built up. So far, I have not removed the actual lightening coil...wanting to test it with my multi meter before I pull it out. The wires coming from the magneto system has 4 wire, 2 black and 2 yellow. I’ll check the compression again later with a different gauge. My biggest issue is trying to figure out why it’s not getting a good spark.
is there a way to bench test the ignition wires/ coil within the small electrical box? I have the SPX with the 720 in it.

 

[KyleW2]

I assume you did as I believe the compression would read lower if not, but did you check compression WOT? I know I have forgotten to do it once or twice and always panic until I realize my mistake.

 

[msmoak5]

I assume you did as I believe the compression would read lower if not, but did you check compression WOT? I know I have forgotten to do it once or twice and always panic until I realize my mistake.

Lol! I actually thought about that, and realized I only took out one spark plug at a time and connected my compression garage and just hit the start button! ‍

 

[mikidymac]

It will not matter if one plug is out or not.

 

[msmoak5]

Did more research...and yep, was the guy that purchased the good ole Amazon/ eBay special for the carb rebuild kit. Just ordered the Mikuni OEM kit, along with new needle valve kit. Pulled the spark plugs and they’re covered in fuel. Prob why my compression wasn’t where it should be. Engine is flooded. I’ll post an update once I rebuild the carbs again.

 

[msmoak5]

Figured I’d give an update...took the stator apart and cleaned it, also rebuilt the carbs with OEM Mikuni rebuild kit. Awesome results! The ski fired up and I actually took on the water the other day and it ran like a champ! Note to self....don’t use the Amazon carb rebuild kit! Basically, the cheaper rebuild kit was causing my fuel to dump into the cylinders and was sealing correctly. Checked my pop-off pressure with the OEM kit and it was within specs. Compression has been fixed too. Taking it out tomorrow...waiting on my induction tachometer to come in so I can adjust the carbs to correct idle.

 

[mikidymac]

Awesome!
Sorry you were a victim of the AM carb kits, but glad you are now enjoying your ski.