My SJ don't take rpm max sometimes (and nobody knows why...)

[optimizaide]

Hi all,
first i'm frecnh so excuse my english!

So here is my issue.
If i"m home ski runs grate, but as soon as i go at sea (thats where i must use my ski right?) after the ride the ski don't whant to take all this RPM, then i go home and he works again...
Sometime he does that at home also but most of the time it is ok.

You can see on this 2 vids the differences between when he works and when he don't

So what i have done already:
-electrics: wheel changed, cdi changed, spark wires and coil changed, my ground and plus wires are new
-carbs: check all the fuel lines from tank to carbs ok, my carbs have been rebuild with mikuni kit and they are actually open on my desk and all is ok
-engine: i have new piston, all gasket are new, redone my head gasket just in case
-batterie: had a lithium battery and try also with a normal on

I talk of my problem with multiple person and noones find what it can be, so if you have some idea ....

 

[JFGJetski]

Have you replaced the spark plugs them self? Do you have a water fuel separator? If so check if that's full, or I'd recommend getting one if not. Sounds alot like a fueling issue to me, I'd double check all your fuel lines and carb, and make sure it's tuned properly

Sent from my SM-G986U using Tapatalk

 

[optimizaide]

Yes, all spark pmugs are new,
i don't have any fuel sparator, i can test with one.
me fuel line seems clean and ok
i tuned my carbs for the Bpipe, but i can check that too

 

[john zigler]

Put some in line spark testers on your spark plugs, and test. Sounds to me like your spark is breaking up. A bad stator coil can do this, runs fine when it is cold, and then breaks up once some heat is soaked in.

Other things we have seen do this as well;

Bad voltage regulator. - Test voltage at your battery while sitting, ( A fully charge battery should be 12.5 volts), and then again while it is running. ( You should see voltage climb when you start, and rev your engine. Should go 13.5 volts or even more)

Bad CDI

Bad ignition coil.

Hope this helps. Please report back with what you find.

 

[te4250]

I would check the stator out for sure if you already replaced all that other stuff, had a stator actually come loose inside my flywheel on a ski and amazingly it would still run good for a while then act very similar to yours

 

[optimizaide]

I don't have this in line spark tester, i will try to find one.
I have already change my stator (not for a new one) last one broke by a broke of a flewwheel key, don't know the name of that one...
I will chek the voltage when i run the ski to check!
My CDI was changed by a OEM one who was in a running ski ( a friend's ski) so i guess it is good but here not sure of nothing!

I have checked me fly wheel with ohmmeter and from what i saw he was okay.... but i will dismount it and check it.

Thanks guys for your help i will check all of that as soon as i can!

 

[bored&stroked]

I have a similar issue with my wave raider right now, first ride is great, then once its turned off and back on after heat soaking it won't take throttle. I too am assuming stator since the CDI and coil have both been changed.

 

[Pro-pulsion]

Could possibly be old worn out crank bearings and seals. If the bearings get too worn out they'll allow movement in the power strokes opening an air gap at the seals. Happened to my old SeaDoo. Nobody could figure it out without pulling the motor apart. I'm the that found it lol.

 

[optimizaide]

Hi guys thanks for your reply, so what i have done, i have open where the stator is and look what i found

plenty of salt inside,
so i check the oring of the generator seems ok, put some grease i put back up
So what i hope is that when im on the water i take some salty water inside and then it makes my stator works poopty, and then back home no more water moving inside and he works good....
So i will remount it with OEM seal and give it a try.... and finger crossed
what do you think? can it be that?

 

[mikidymac]

It looks like you had some moisture in there at one time but it’s definitely not “full of saltwater” or your stator and flywheel would be a rusty mess.

 

[optimizaide]

It looks like you had some moisture in there at one time but it’s definitely not “full of saltwater” or your stator and flywheel would be a rusty mess.

Yes maybe i axagarated ahah so you think that even with the water inside and heat maybe that cant cause my issue?

 

[waxhead]

What does it ride like on the water, I mean you are testing it on the trailer but no one rides there

 

[optimizaide]

What does it ride like on the water, I mean you are testing it on the trailer but no one rides there

we are 3 of them tested on the water and no one can tell it is not working properly, but maybe because we are not full trottle enought to feel it.. i don't know
i have clean and put back, im waiting for the OEM gasket and gonna test

 

[Harbor]

You can Pull the starter back out and put a bead of RTV Silicone, (in a ⭕️ circle) all the way around the staters end where it butts up against the engine case.. This will act as a pre Barrier, so water can’t get at the orings on the nose..

 

[optimizaide]

You can Pull the starter back out and put a bead of RTV Silicone, (in a ⭕️ circle) all the way around the staters end where it butts up against the engine case.. This will act as a pre Barrier, so water can’t get at the orings on the nose..

arf i have already put it back, i have putr some grease, i will do it if i need to put back out the starter!

 

[waxhead]

we are 3 of them tested on the water and no one can tell it is not working properly, but maybe because we are not full trottle enought to feel it.. i don't know
i have clean and put back, im waiting for the OEM gasket and gonna test

I think you are worrying about something that doesn't need worrying about then, A ski will foul its plugs if you start it to many times on the stand as it has no load and chamber heat

 

[optimizaide]

I think you are worrying about something that doesn't need worrying about then, A ski will foul its plugs if you start it to many times on the stand as it has no load and chamber heat

so you think that on the video i put it is something i dont need to be worried?

 

[waxhead]

so you think that on the video i put it is something i dont need to be worried?

if its playing up on the trailer but you cant tell in the water ?? then yes

 

[optimizaide]

if its playing up on the trailer but you cant tell in the water ?? then yes

yes, it starts when i just put out of the water after a ride, and run normally when i come back home usually

 

[OCD Solutions]

Could it be that you are experiencing water loaded up in the water box and pipe?
The same thing happens when you flush a ski on the stand at low rpm.
Once you are done flushing and try to rev up the engine to clear out the water, it just bogs and is slow to rev but as you keep it up and the water clears, the throttle response gets crisp again until soon it is firing off nice and sharp again.