I have had my 1997 Seadoo Speedster (it has two 787 motors) for almost 2 years and have tried my best to keep up with maintaining it. I use it for wakeboarding and tubing and put it away in my garage where it sat for probably 3 to 4 months without use. My Seadoo starts right up but I don’t here any beeps. I have only heard the boat beep like for a few months on and off. My gauges worked in the begging but have died one by one and now not one of them work yet the boat starts up. The RPM gauges don’t work, while one stays completely below one and the other below one but not as far down as the other. I just recently took the boat out for a spin and started the motors up in the water just fine. I was just about ready to take off and the motors would deliver more power and begin to shake more than there suppose to, almost like something was stuck in the impellers. So i shut the motors off and put the boat back on the trailers and removed some weeds. I placed it back in the water and it repeated the same thing but this time the impellers were free of any debris. I once ran low on 2 cycle oil in which the motors began to do what they are doing now. I don’t think I harmed the engines when I did that because the boat has run pretty good since then because that was like a year ago. What I did notice though was that there is an excessive amount of 2cycle oil in the bottom of the hull. So what I’m wondering is if my oil mixture is causing my engines not to increase speed and create a violent shake. I tried to find where the leak was coming from and all that I found was most of the oil spillage is coming from the hose that’s located on the bottom. It’s the biggest hose not connected to the block or the carb but the other one. If anyone can help me with any and all my problems with my boat I would greatly appreciate it. I like this boat very much and I’m very handy, considering I have replaced one carb and built the other, as well as replace a throttle cable and shifting cable which was not fun, I have a little knowledge but not enough. Thanks For any help Mike.
1997 Seadoo speedster problems
- Thread starter jmmshop
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I would take a compression test first of all. With the plugs out during compression test look to see if there is any oil spitting out of the spark plug holes. I would be sure it has fresh fuel and plugs.The big hose goes back to the injector tank it lubricates you rotary valve gear shaft in the rotary chamber. Check the hose to be sure it isn't split or cracked, causing the leak. The beeper could be bad. Inside the storage area is the wire connector that it connects to. Use a volt meter of a multi meter to check it for voltage. you can replace it at radio for like $12.00. I don't think I forgot anything to address. Let us know how you make out.
Karl
Karl
1997 Speedster problem
I just finished checking the compression and I have 140 for all four. No oil spitting out and pretty clean spark plugs. What else could it be? What else can I try before I drop it in the water tomorrow to test it in the water again? Could it be anything dealing with jet pumps or hoses or the mixing of the oil and if so what do I do? I tried to feel for cracks in the oil lines but I didn’t see any or feel any. The lines look decent although I can’t se under the motor but I felt it. Felt fine. But when I mean oil in the hull I’m talking not just a little but maybe 1/3 of a quart. And the weird thing is that it's not just one engine that's giving the shaking and problems it's both. They both have oil under them in the same locations. Please let me know what my next steps are thanks so much, Mike
I just finished checking the compression and I have 140 for all four. No oil spitting out and pretty clean spark plugs. What else could it be? What else can I try before I drop it in the water tomorrow to test it in the water again? Could it be anything dealing with jet pumps or hoses or the mixing of the oil and if so what do I do? I tried to feel for cracks in the oil lines but I didn’t see any or feel any. The lines look decent although I can’t se under the motor but I felt it. Felt fine. But when I mean oil in the hull I’m talking not just a little but maybe 1/3 of a quart. And the weird thing is that it's not just one engine that's giving the shaking and problems it's both. They both have oil under them in the same locations. Please let me know what my next steps are thanks so much, Mike
I almost forgot, welcome to the seadoo forum Mike. Is the fuel fresh? It could be that the carbs could be a little gummed up. I would also check the fuel separator for contaminates. As far as the oil, follow the oil injector lines to the tank and look under the fittings to see if the oil is leaking and following the line to run under the engine. I would check all the oil lines. Be sure the lines are tight on the ends, and the clamps are tight. It has to be coming from somewhere. Keep us posted on what you find.
Karl
Karl
The tank was empty and I put new fuel in the day I took it out and it gave me that problem. And when you mean fuel separator are you talking about the clear container next to the oil reservoir. I check it and it seems to be fine. I rebuilt one of the carbs not to long ago and the other is brand new also replaced about a year ago. When I had it started it didn’t seem to be a carb problem. Do you have any other ideas on what it could be or do you need me to describe the problem in more detail so you can better assess it. thanks for your help so far and I’m sure we will come to some solution, thanks Mike.
How long ago were the RAVE valves cleaned? If it was longer than a year ago it could be that they need to be cleaned.
Karl
Karl
The RAVE, (Rotax Adjustable Variable Exhaust) valves are located above the exhaust valve.There are 2 of them per engine. They are round with a red adjustment screw in the middle. It has a clip that holds it together. How they work is that they open the exhaust port larger as the engine rpm's increase. When the rpm's drop down so does the RAVE valve. On the 787 engine they work on the principle of the pressure of the exhaust system. rpm's increase, pressure increases and the valve opens, rpm's drop pressure drops, Valve closes. They should be de-carbonized annual. To disassemble the rave valves, remove the spring clip on top, remove the black cover. There is a spring under the cover. Remove the piston by turning it with a metric socket. On the bottom of the piston is the rubber "Bellows" be careful with the small retaining spring that hold the bellows on the piston. Remove the 2 allen screws that hold the base on the cylinder. Remove the base and gasket. The long valve won't fall in the cylinder just pull it out. There is an o ring under the base, on the shaft of the guillotine valve. Be careful to see how it came apart as it has to go back together that same way again. On the base, notice the notch that it is facing down. Clean all the carbon off the guillotine valve. I use carb cleaner and 400 grit paper. Check the bellows for any small pin holes. If so replace it. If not, reassemble it on the clean guillotine valve, and install it back on the engine the same way it came apart. The guillotine valve only fits one way. The one closest to the exhaust pipe will come off differently then the other one. You will have to remove the allen screws and turn the base so it clears the exhaust pipe. I would do one at a time in case you forget how it goes back together again. This way you can look at the other one and copy it. Do both engines 2 per engine. Take your time and if you have questions give us a shout. We'll be here to help you out.
If the RAVE valves are dirty it will not rev up correctly and could be causing your problem.
Karl
If the RAVE valves are dirty it will not rev up correctly and could be causing your problem.
Karl
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where to locate the rave valves
I believe I had a 787 motor but maybe it is a 717 because I have seen a few 787 with the rave valve description you described. Mine does not have those two rubbers above the exhaust manifold. I have the other type of engine where the pistons are vertical. Please let me know where to look. Thanks Mike
I believe I had a 787 motor but maybe it is a 717 because I have seen a few 787 with the rave valve description you described. Mine does not have those two rubbers above the exhaust manifold. I have the other type of engine where the pistons are vertical. Please let me know where to look. Thanks Mike
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