No power WOT & Buzzer Silenced

[gtxnoclue]

My 1996 GTX will run great for a short time then bog down at WOT. Then it will start running ok for awhile, then bog down again (and again). When bogging down it reaches ~3500 max rpm. I noticed that the wire from the temperature sensor had come detached from the sensor at some point. Reattached it, cleaned the fuel filter, checked compression (ok), & checked fuses (ok). Seemed to run better for longer but then same thing occured. Bought a Clymers manul to see if it would help. Cleaned all wiring connectors (contact cleaner & dielectric grease), pulled out the CDI module & tested it per the specs. Have an open between the white/black wires (only one direction - negative lead to white wire; The other way seemed ok). Only issue is that the specs call for a black/grey wire which I don't have on that module. I may not have the correct CDI module or spec sheet.

Regarding the buzzer - At some point in the process I noticed that the buzzer will sound when expected - but barely audible (eg when plugging in the key). Took the buzzer to a boat shop who connected it to a car battery (go figure) and it worked. I had previously hooked it directly to my seadoo battery & it was barely audible. After it worked at the shop it worked fine when plugged in directly to my sea doo battery. Put it all back together in my craft & then it was barely audible again. Hooked it directly to my seadoo battery and again - barely audible. Not sure if more current than usual jarred it into working for awhile or if something else is causing it to not sound well. Hooked the leads up to the buzzer input, plugged in the "key", & only saw ~1.2V (~6V when hitting the starter switch 5 times). I'm not sure of the response time of my meter, though.

Any suggestions before I take it into a repair shop for both issues would be greatly appreciated. Not sure if the issues are related or not. I'd love to figure it out & fix it myself.

PS - not sure if it matters but last year the engine compartment flooded (long story but I don't plan on taking it back the repair shop that fixed a slow leak & caused a submersion...). Hence me trying to fix it myself.

Thanks!!!

 

[seadoosnipe]

Forget the buzzer......

The buzzer isn't somthing I'd be concerned with at the moment. Getting the ski to run, is what we should be focusing on.....You can get any small 12 vdc light bulb or buzzer from radio shack, if needed. The only thing you may want the buzzer for, is to make sure your getting 2 beeps for starting.

You have the 787, so bogging may be caused by the RAVE valves sticking, which are supposed to be cleaned yearly and will cause bogging in the 3500 to 4000 rpm range if they are stuck closed. The age of the ski, it's possible it's time to rebuild the carbs if that hasn't been done in the last couple years. That's also assuming you no longer have the grey fuel lines. If so, replace them.

The temperature sensor isn't going to have any effect on the operation, unless it gets hot.

The shop. The ski is over 10 years old. The shop is going to shoot parts into it at your expense until they hit the right one........You may be best served in doing these couple things yourself, if you can work on a lawnmower engine.:cheers:

 

[kustomkarl]

Here is some info on the rave valves;
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 do the RAVE valves. 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 holds 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, if so equiped. 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.

The adjustment knob (the red cap) should either be screwed all the way in or flush to the top of the black ring of the cap. This will only affect performance, as far as how it jumps out of the hole or how well it runs for extended periods at WOT.


Karl

 

[gtxnoclue]

Wow

Thanks so much for the quick replies! Was exploring the forum as I'm a new user & went back to look at my message & already have both of your responses. WOW! Thanks again!!

I'll start on the RAVE valves tomorrow. They haven't been cleaned at all in the last 8 years as far as I know. During my search on the forum I also saw several other posts about getting rid of the grey fuel lines (per your reply to my post as well). Hope to get on that tomorrow as well. I won't tackle the carb filter cleaning/rebuild until after seeing what happens with the RAVE valves.

PS - never worked on a lawn mower engine either.... We'll see how this goes.. ; )

Again - I can't believe the super quick, expert advice. You guys are life savers!

 

[kustomkarl]

Keep us posted on your progress. If you get in a bind give us a shout.
Do you have a seadoo shop manual? If not here’s an idea for you. You could join as a "premium member". As a premium member you can down load a authentic seadoo manual from the seadoo manual library. In the library is a variety of manuals for almost all years and models. You can view as many as you like on line as a PDF file, or download it and print it for your personal and private use. There are operator manuals and repair manuals for you to do your own repairs on your seadoo. The repair manuals have everything from troubleshooting, repair procedures to winterizing. It contains wire diagrams torque specs and pictures for disassemble and assemble instructions. In the spec sheets it tells everything needed to maintain oil changes, spark plug gaps, carburetor rebuilds and impeller wear ring tolerances. Click on the "Seadoo Manuals" link at the top of the page for more details. If you need any help or get in a jam, we are always here to answer your questions too. Premium members get priority when it comes to getting quick detailed answers.


Karl

 

[seadoosnipe]

Grey fuel lines.......

If you do have the grey fuel lines, that should be your starting point.:cheers:

 

[gtxnoclue]

I'm pumped - stayed up until 2:30am disassembling & cleaning RAVE valves. Boy were they nasty. I'll try to attach some pictures (pix to big - I'll try later). I hope it solved my bogging problem. I'll put the craft in the water later today to check it out.

I'll definitely look at the premium membership as well. The Clymers manual I bought was a help, but I didn't see anything in it on the RAVE valves and it wasn't listed in the annual maintenance recommendations.

Time for a shower & some coffee...

 

[gtxnoclue]

Progress

Put the seadoo in the water. The 1st 100 yds was rough running at low throttle. Then it ran GREAT for ~25 minutes. Then it bogged down again at 3,000-3,100 rpm. Did this for about 5 minutes. I cycled power (via starter button & pullling lanyard off) a few times. It then started running great again for another 20 minutes. I'm letting it sit in the water for a bit to ensure I didn't create any leaks (I also spliced broken speedo wires while it was out of the water).

I will have to replace one of the springs that hold the bellows to the piston. One broke last night - I was able to "splice" it for a temporary trial.

Interesting note: The alarm buzzer mysteriously started working at normal volume after running the craft for awhile... It did NOT work on the trailer prior to putting it in the water...

Couple questions:
- Will it take a while to clear the debris in the exhaust system from the nasty RAVE valves?
- If not, does it sound like a carb rebuild & fuel lline replacement is the next step or is there an interim solution that will allow me to limp through the next 2 months (carb rebuild sounds like a good winter project)?
- Any recommendations on where I should/could order the spring?

Thanks again for all the help!!!

 

[timmyboy76]

do rebuild on carbs, and spring latch,...can order from "parts" tab on this page, rebuild kit,...seadoosource.com, parkeryamaha.com....:cheers:

 

[gtxnoclue]

What is a "Spring Latch"? On Sea Doo's website I couldn't find it listed on either the Mag or PTO carb parts list. Is this a part in the carb or separate? Also - do you know if I have a MAG or PTO carb (or does it matter - especially when ordering a carb rebuild kit)? I assume I won't need the Accelerator Pump Diaphragm since it looks like its for 97 models and after...

I also didn't clean the engine side "hole" where the RAVE valves fit. Can that still be contributing to my now "only occasional" bogging?

Thanks again for all the help.

 

[timmyboy76]

"I will have to replace one of the springs that hold the bellows" ....thats what i described as"spring latch",..latch hold'n bellow cover down(where red dot is).?
you have (2)BN-40I sq, body carbs...mag carb is the one closest to flywheel/magneto housing, pto carb is by the grey shield...also, if havn't done, pull the raves/geotines and clean them...

 

[gtxnoclue]

Thanks for the info on the spring latch & also for the carb description (yes I'm a novice...).

For the carb rebuild - do I need the Accelerator Pump Diaphragm for my 96 GTX? I don't think so from what I've read but just want to make sure.

Thanks!!!

 

[gtxnoclue]

Picture of Dirty RAVE Valves

Thought you'd be interested. They were pretty nasty...