Rotax 657x power lost.

[Anders]

Hi all

I have a Seadoo sportster -95 with one "Rotax 657x".
Now to the problem.
If I start and get full power direct it works for aboute 10 sec. Then I lose all the power and the boat runs in 10 knot. And it will not go faster.
I have get the carburators fixt, gasolin filter and new Ignition coil.
And lookt at propulsion system.
Eny one have any ideīs??????

Thanx

[dsolie]

Re: Rotax 657x power lost.

Try unplugging the rectifier.

**warning.. doing so will make it so your battery won't charge while the ski is running. Unplugging it is only to be used for diagnostic of a bad rectifier **

[Anders]

Re: Rotax 657x power lost.

OK Thanx, I will try that!

[Anders]

Re: Rotax 657x power lost.

Hi again!
I have try to unplugg rectifier. No luck.
My SeaDoo mekanic here in sweden have no more to try.
He have lookt in to all he can.
The fanny thing is that the boat works if I start and full power immediately (for 10sec) if I shut off the engin and wait for 10 min, and start it works again for few secons.
I have try to fix this hole summer with no luck.

Please do you have more ideaīs?

[dsolie]

Re: Rotax 657x power lost.

How did you unplug the rectifier? There are a couple different ways and on that X motor, it makes a difference


1) You could have a bad coil that is getting overheated
2) Vent lines in tank working? Next time it happens, open the gas cap see if that helps.
3) Were all the grounds and connections dry and corrosion free in the elec box?

[Anders]

Re: Rotax 657x power lost.

Hi

In the electrik box I disconnect the 3 cables (se the rings in the attatch)

Answers
1. I have try with a new Coil (se the skvare in the attatch)
2. Havenīt try i........sorry will do.
3. Yes, looks like new.

Thanks

[dsolie]

Re: Rotax 657x power lost.

Whats your compression?

[Anders]

Re: Rotax 657x power lost.

aboute 79,6 psi.
and not mor then 5% dif.

[dsolie]

Re: Rotax 657x power lost.

Time to open up the front cover. To me it sounds like the ski is going into a one cyl run mode. New coil, checked rectifier, checked elec box.. Options are now the stator, MPEM, CDI and Rev Limiter.

or...
A ground is corroding somewhere and getting hot and loosing continuity, once it cools down it's fine again until it heats back up again.

[John Kubiak]

Re: Rotax 657x power lost.

aboute 79,6 psi.
and not mor then 5% dif.

Are you sure you are using the correct unit of measure? You may be reading in "bar" and a value of 7.96 bar is about 115.45 PSI. If this is the case you are ok, but slightly low on compression.

[Anders]

Re: Rotax 657x power lost.

The measure is 6,5 kg (the term in sweden).
My Seadoo tecnicer sade it is normal an no wrong with the measure.

[Anders]

Re: Rotax 657x power lost.

Time to open up the front cover. To me it sounds like the ski is going into a one cyl run mode. New coil, checked rectifier, checked elec box.. Options are now the stator, MPEM, CDI and Rev Limiter.

or...
A ground is corroding somewhere and getting hot and loosing continuity, once it cools down it's fine again until it heats back up again.

My Seadoo tecnicer think it can bee the electrik box, but I donīt realy want to order one from Canada for 1000$ if it is no wrong with the one I have.
Is it not a way to see if the box is ok?
Do you know if I can get one "used" sheeper?

[seadooman48]

Re: Rotax 657x power lost.

sounds like a restriction in fuel sys check all fuel lines for blockage and check fuel on off valve for blockage

[Anders]

Re: Rotax 657x power lost.

My Seadoo tech have looked on the fuel, end no prob. and I donīt use the valve. always opend.

Iīm in to that somthing is "overheating". If I think on the symtom.
If it is fuel it chud work afer a wild agen, but I have to turn off the enging and wait. (somthing is coolingdown).

Thanx