2001 Seadoo Sportster LE. Just got it!
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Sportster-2001-951C-Stock
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Agreed, I would epoxy hardwood wooden blocks on the inside and use them to affix/stabilize the mounting, also clean up the wiring.
Sportster-2001-951C-Stock
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The two on the engine are power valves, they control the exhaust port opening size. At low speeds they are down in the closed position and at higher speeds/power they open to increase the size of the exahust prots. They're called RAVE valves, Rotax Adjustable Valve Exhaust.
You might need to remove and clean them if they haven't been cleaned recently, removing to clean should be done once per season at least, I prefer to do this during winterization. If they aren't cleaned preiodically they may stick open or closed. If stuck open, the engine will run rough at low speeds, if stuck closed the engine won't develop full power.
The valve that looks similar on the exhaust water box is a water valve, it controls the amount of water injected into the tuned exhaust expansion pipe, for both cooling the pipe and tuning the sonic resonance of the pipe. at low speeds there is maximum water injected into the pipe to shorten it's length. At higher engine speeds, less water is injected and the pipe goes to work to work as a sort of sonic turbocharger. There are no moving parts inside the expansion pipe, the amount of water injected tunes it's resonant frequency.
All remaining "unused" water is dumped by the valve directly into the water box to cool the exhaust gasses. If the water valve malfunctions, there may be a lack of water to the expansion pipe and the large rubber coupling connecting the water box to the expansion pipe can burn through from excessive heat.
Bonmotwang
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I think I figured it out: it is the generator for charging the battery.
Sportster-2001-951C-Stock
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If you mean the rear "e-box", it's the box that houses the two ignition coils and the starter solenoid, along with the main system fuse.
It has a lid on top held by three prongs and a rubber gasket around the lid lip to seal and keep water out.
It's shown here in the electrical schematic on the right side, called "Rear Electrical Box":
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Bonmotwang
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Thanks! I am an electronics designer/consultant. You are talking my language!
Sportster-2001-951C-Stock
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Okay, in that case the alternator you're looking for is under the front cover(magneto cover) of the engine, it's a multi pole winding wired in three phase "Y" as you can see in the upper right corner of the schematic with a rotating permanent magnet on the flywheel. The rectifier/voltage regulator is integrated into the MPEM and is three diodes in series with three SCR's triggered by a rather standard couple of PNP transistors + zener combination something like this(but slightly more sophisticated) all sealed and potted in the MPEM:
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Sportster-2001-951C-Stock
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There are three or four grounds inside that rear e-box all tied together by a screw threaded into a plastic post, this looks kind of cheesy to me and could become an issue at some point. I have a plan to drill the post straight through the bottom of the e-box and install a corrosion proof screw with nut and washer(s) to make it more reliable.
Bonmotwang
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Yes, that 12V Zener could be something like TL431 to give a better reference voltage.
Bonmotwang
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I agree. If that that grounding fails, many things will be open circuit.
Do you have know what do they do for the grounding path/plane? All go back to MPEM through cables then one wire to the battery negative?
Bonmotwang
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V.T.S module
Is the VTS mechanically controlling the jet nozzle up and down to adjust how high the bow will be raised?
I saw a VTS motor in the diagram. Just wondering.
Is the VTS mechanically controlling the jet nozzle up and down to adjust how high the bow will be raised?
I saw a VTS motor in the diagram. Just wondering.
Yep,, that's correct...
Bonmotwang
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Wow. This is neat. I will check mine to see if it mechanically looks ok.
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Bonmotwang
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947/951 engine carb
I have been watching you tube videos for 951 engine rebuild and repair.
From what I can see, to build the carb, you need take the whole engine out and then you can take off the carb.
Is this true?
Or you can remove the exhaust and then you will be able to access the carbs.
I have been watching you tube videos for 951 engine rebuild and repair.
From what I can see, to build the carb, you need take the whole engine out and then you can take off the carb.
Is this true?
Or you can remove the exhaust and then you will be able to access the carbs.
Sportster-2001-951C-Stock
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My boat doesn't have VTS, I don't think your does either? That schematic diagram is for the XP ski, it does have VTS. It's almost the same otherwise, I don't know of any other differences.
I can remove the carbs in about 10 minutes, they are easy to remove. I climb into the bilge to remove the throttle cable and fuel line from the carburetor fuel pump, the rest I can remove by leaning over the rear seat. No other disassembly required.
Be careful removing the fuel return line, the fitting is plastic and looks easy to break off.
I can remove the carbs in about 10 minutes, they are easy to remove. I climb into the bilge to remove the throttle cable and fuel line from the carburetor fuel pump, the rest I can remove by leaning over the rear seat. No other disassembly required.
Be careful removing the fuel return line, the fitting is plastic and looks easy to break off.
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Bonmotwang
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Thanks. Otherwise I will be very disappointed tonight by finding out my VTS is gone. :-D
Are the carbs underneath the big exhaust port?
I searched and searched around Internet, just could not find a clear view showing where are the carbs. (I thought the RAVE valves are until you told me)
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Bonmotwang
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Because of this reason. Is it possible the PO changed the filter to let 2 stroke go through?
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Sportster-2001-951C-Stock
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This little filter strainer is an inline type in the delivery tube from the oil tank. I circled this tube(but not the filter) in your photo, the filter is just a few inches down from the red circle, can't be seen in the photo. It's a special filter, low restriction oil strainer type, so if you replace it then be sure to get the right one or the oil flow will be restricted.
Other possible electrical differences (ski vs boat):
We also have a neutral start interlock switch in the reverse/neutral/forward shifter, I don't see this one on the 951 XP-ski schematic, maybe I overlooked it. The starter won't crank motor unless the shifter is in neutral position(no beeps!). Does your beeper work (chirp, chirp)?
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Sportster-2001-951C-Stock
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The carbs are located on the port side of the motor, just under the black exhaust manifold. There is a black plastic air silencer box over them that clips on with a single stainless clip at the top, pull the clip and the air box pulls off the reveal the carburetor intakes.
I think you can find the 2001 shop service manual for the jetski, and use this for a great deal of info. Obviously the boat uses a slightly different hull and the seating is slightly different, too. Same motor though, and many other parts.
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Bonmotwang
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My beeper is working and beep short 2 times. The starter won't crank unless the shifter is in Neutral. First time I tried to start, I didn't put the shifter to Neutral. I thought the battery is dead :-D
Bonmotwang
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I found it by climbing into the engine bay. (it is bigger than I thought :-D)
View attachment 22381
Is it the right type or original?
Bonmotwang
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Ok I think I see it now and understand how to get it out.
That black thing is the silencer.
Thanks
Sportster-2001-951C-Stock
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Yes, the oil filter strainer is circled in your picture here, it looks just like mine does. If you disconnect the tubing from it, the contents of the oil tank will quickly run out, so be prepared to catch it in a container. When putting everything back together, be sure to avoid getting air bubbles in the oil line, air bubbles can interrupt the oil injection system:
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Bonmotwang
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Nozzle missing a piece
My boat doesn't have the vertical divider. Is it broken?
My boat doesn't have the vertical divider. Is it broken?
Sportster-2001-951C-Stock
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I don't know where you found that photo, but it doesn't look anything like my boat either. My jet pump has no divider in the steering nozzle, I'm glad it doesn't.
BTW while we're on the subject of steering, remember that a jet boat doesn't have a rudder, so it won't steer if the engine isn't running. I haven't seen any nozzle rudders on a seadoo jet pump.
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