Super Jet Worn through ground wire cause running issue?

[nightrider05]

I can go in to more detail later, but my ski went from running great, to acting like it is in limp mode. I have swapped nearly every electrical component chasing this issue down, and just came across this worn through ground wire.

So can a worn through ground wire cause ski to not run crappy?Almost sounded like it's running on one cylinder and can't open up.

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[nightrider05]

Meant to say "run crappy"...not "not run crappy"...it won't let me edit it on tapatalk.

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[Freakie]

Highly unlikely that is the cause....its only just exposed the wiring....however.....if the exposed part was chaffing on the red lead or battery positive.....then you just got lucky you found this before things got ugly.......if the chaffing was caused by exhaust, motor rubbing on lead, etc.....won’t affect running.....assuming black lead is tightly attached to battery negative
Does the motor rev freely out of the water....if so....what exactly happens when you try to ride it

 

[nightrider05]

Highly unlikely that is the cause....its only just exposed the wiring....however.....if the exposed part was chaffing on the red lead or battery positive.....then you just got lucky you found this before things got ugly.......if the chaffing was caused by exhaust, motor rubbing on lead, etc.....won’t affect running.....assuming black lead is tightly attached to battery negative
Does the motor rev freely out of the water....if so....what exactly happens when you try to ride it

I was doubting this would be the issue, but it was worth a shot. Either way it needed to be fixed.

Ski sounds "Ok" on the trailer..once under a load it falls flat on its face off idle. It was running great...did a decent wide open run and then it acted like it fouled a plug. It had done this once before and new spark plugs solved it. I also noticed it was very rich at that time.

I had a similar issue with another ski years back and it ended up being the stator. I swapped the stator on this one and same issue. I've also tried a different MSD, and went through carbs (found a leak in gaskets and leaky throttle shafts..replaced with a minty set with new oem kits).

I've also checked the reeds, pressure tested motor, and changed most electrical components with spares from the shelf. Compression is 180 psi per cylinder. Nice blue spark. Wires have been trimmed, resistance on secondary coil is around 24k (on high end..may change coil out again with one with lower resistance). Only other symptom I've had is a draining battery. Battery voltage is 12.6-12.9 while revving which does seem low, but I've found other posts saying that's normal. Voltage regulator is giving me some odd readings compared to manual specs.

There's a possibility some of my spare components are bad, but test ok.

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[nightrider05]

If someone could confirm what the voltage at battery should be while running, that would be helpful.

My fx-1 is around the same number(12.9 while running)

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[Harbor]

If someone could confirm what the voltage at battery should be while running, that would be helpful.

My fx-1 is around the same number(12.9 while running)

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Just starting and running without water, quick test.. I've gotten 12.8 ish... basicly .2 volts above battery voltage

 

[nightrider05]

Just starting and running without water, quick test.. I've gotten 12.8 ish... basicly .2 volts above battery voltage

Thanks for checking. I've read some places say 13.5+ which was throwing me off.

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[Harbor]

Thanks for checking. I've read some places say 13.5+ which was throwing me off.

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I've seen that 13+ as well but it was after a lot of cranking a new engine and running it in on the stand with water hooked up.... so charging system started cycling in...

But the Last 3 I did quick tests on checked out 12.8 ish and all 3 had no charging issues..,

 

[Freakie]

I am angling towards fuel starvation....how old is/are external fuel filters....replace it anyway....did you clean embedded filters in carbs....can you verify that excess fuel is returning to tank via return pipe..(decent flow) ..one one way check valve on gas tank working properly.

 

[nightrider05]

I am angling towards fuel starvation....how old is/are external fuel filters....replace it anyway....did you clean embedded filters in carbs....can you verify that excess fuel is returning to tank via return pipe..(decent flow) ..one one way check valve on gas tank working properly.

Thanks for the reply.

Carbs were the first thing I looked at. It has a ported TLR 735cc motor with dual 44s. I noticed throttle shafts were sloppy. I had a mint dual 44 set on the shelf so I swapped everything over and rebuilt with Mikuni kits. Popoff was very high..over 30psi. I lowered that to roughly 18 PSI. Carbs were ultrasonic cleaned as well. Fuel lines have all been removed and blown through, as well as the fuel selector switch. Fuel filter was replaced(old one looked fine). Fuel tank was drained and checked for water. One way check valve has been verified to be good(was bad when I got the ski..replaced it a couple months back). Holds around 5-8 PSI one way and flows free the other way. Its dumping plenty of fuel in when running on the trailer..nice spray going in to carbs.

Reeds have been removed and verified good. Motor has been pressure checked at 10PSI and held that for hours...still had 7psi roughly 12 hours later(PSI drop attributed to a leaking pressure tester connection).

Other parts that have been thrown at it: Stator(both tested fine, just wanted to verify and check timing while I was at it), Voltage regulator, new MSD enhancer, Coil(trimmed wires...resistance is around 24k with no boots..seems a tad high so I may swap in another one with lower resistance), Start stop switch(plugged in..not mounted to handlebars which shouldn't matter), new ground wire(no change).

Im really at a loss on this one. I've water tested after each repair that way I would know which component fixed the issue.

The only other info worth noting is that I had a backfire the day it quit running right. I went to a Wisconsin jetski ride and it backfired as soon as I put it in the water..blew an exhaust hose off the waterbox. I'm sort of curious if maybe I have a baffle blown loose in the waterbox. It doesn't sound any different but an exhaust restriction would definitely cause some issues.

 

[nightrider05]

I also verified that the flywheel key was not sheered when flywheel was removed to replace stator.

Dual cooling fitting was broken on the pump, so the exhaust was also running a tad hot. Did melt the sheathing off the start stop switch harness but not into the wiring.

So much poop to fix. I can't believe what some people consider good build quality. Luckily this issue has allowed me to find a bunch of others and repair them.

 

[Freakie]

Seems like you have checked and replaced pretty much everything already....only one comment....not sure what pipe you are running but 18 psi pop off is very low......Stock is around 45..ish.....mid to upper twenties normally bang on for most mods......others can chime in

could be running way too rich low down causing plugs to foul instantly....just a thought

 

[Harbor]

There's a possibility some of my spare components are bad, but test ok.

Can you try a known good cdi ?

 

[nightrider05]

Update for anyone following. I wasn't happy with the one coil I had put in since its resistance was reading 24k(some specs say thats ok, others I found say not ok) so I put in one that had 4.5k resistance. I also rewired ebox following a diagram. Ski ran great for 5 hours!

But then a new problem occurred which seems similar. I did however make a couple carb adjustments right before the new issue arose, so I am going to dial it back to where it was and see if I caused the latest problem.

Can you try a known good cdi ?

Tried 3 actually..a brand new MSD and a stocker. Same results.

Seems like you have checked and replaced pretty much everything already....only one comment....not sure what pipe you are running but 18 psi pop off is very low......Stock is around 45..ish.....mid to upper twenties normally bang on for most mods......others can chime in

could be running way too rich low down causing plugs to foul instantly....just a thought

When I first got the ski it was running around 35 psi popoff. I was told by a buddy that tends to be a tuning guru that it was way too high and to aim for 17-22. Guess I will need to do some playing with that. One odd thing I noticed is that my front cylinder seems to be running more lean than my rear cylinder. This makes me think there is an air leak somewhere in the intake side, even though I used new gaskets on install.

For the 5 hours it was running yesterday, the ski did hit pretty hard on low end, and ran good on top end(although i limited those runs since I had made carb adjustments)

 

[nightrider05]

So for anyone who was following this saga...

It kept going. Multiple things had been tried with the issue being intermittent still(but running like crap and bogging 90% of the time)

Ironically I made a post back on July 4th saying I wondered if it could be a blown baffle in exhaust.

Well, I just got around to checking that. Sure as poop..found a broken baffle that was blocking the exhaust intermittently.

Good news is I now have a Zeeltronics 760 setup, and found many issues along the way!

Water testing this evening but im pretty confident the broken baffle was the issue.