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  1. #1
    Joined
    Jan 2003
    Posts
    167

    Post

    I need some help diagnosing a strange failure of a 98 GSX-L. Here are some pictures:

    http://home.houston.rr.com/thompsdwp...lure%20001.jpg

    http://home.houston.rr.com/thompsdwp...lure%20002.jpg

    http://home.houston.rr.com/thompsdwp...lure%20003.jpg

    http://home.houston.rr.com/thompsdwp...lure%20004.jpg

    The crank had 10 hours on it when I purchased it. All bearings looked good and I rode it all season without any damage. The ski is ridden in brackish water, but religiously flushed and maintained. What is amazing to me is that the rust line suggests a significant amount of water (reguardless of salt content). I guess if the base gasket catastrophically failed, I could have pushed a significant amount of water into the engine when flushing. But that is a real stretch to me. I did notice some areas on the gasket surface where it is shinny, and some that appear to be blackened. But this appears on both cylinders (failed and good cylinder).

    Any ideas?

    [ November 08, 2003, 07:54 AM: Message edited by: dean thompson ]

  2. #2
    Joined
    Feb 2001
    From
    Glendora, Ca.
    Posts
    5,204

    Post

    This post from me is addressing most of the many ways a motor can fail from having water inside of it. It may or may not be what has caused your problem, but chances are your problem is covered here.

    What I am looking at in your pictures is a motor that failed due to water that sat in the cases during a storage period. I see many exactly like this one.

    A waterline on the cases and crankshaft indicates alot of water was inside of the motor for a given period of time. I suspect that you have a direct leak from a base gasket, or a small crack in between a water jacket and the internal side of the motor or clyinder. Another place that isn't widely known about is water that can leak from behind a sleeve and down into the cases. Sometimes we have to remove a sleeve and put a bead of sealant under the top flange of the sleeve and re-press the sleeve back into the clyinder, making sure it is seated, then resurface the top deck of the clyinder. Sometimes we find a sunken sleeve that sits too low, not allowing the head to properly seal the water from the internal part of the motor, too. In fact, that is common on some clyinders that are getting aged or have been rebuilt.

    It is not a design defect as so many have claimed in all of the forums. It is simply because the water had not been removed before storage. But it can be one of the above problems with the sleeves or gaskets on a motor that has been used, abused and rebuilt.

    Water can get in there during riding or flushing. I doubt your base gasket was the culprit, although that is possible. Water can leak from a base gasket breech into the cases. It could have been the exhaust gaskets that leaked on the exhaust manifold, or the way it was flushed.

    Sometimes I see this after a client has flipped the ski over in the water, dumping the water that lies inside of the exhaust system into the motor. Then, after a failed attemp to start the motor, tows it to shore and trailers it home, never getting it started and running until the damage is done.

    I see alot of this each spring after the long storage period of winter.

    From your post, I know that you think you had it clear of water before storage, and maybe you did, and the water leaked from the water jackets into the cases after you finished flushing it through a breeched gasket or crack in something. But the crankshaft and cases tell me it had water in the motor when it was stored.

    Doing a pressure test of the engine after assembly, with the exhaust manifold installed and blocked off, would have shown if it had a leak and was destined to failure from the get-go, witch I suspect was the problem here.

    This is one of the more important features of having SBT rebuild an engine for you. Not olny are all gasket surfaces throughly cleaned, most surfaces are machined to assure of a good seal, then the engines are all pressure tested before shippment. The only place that the customer can make a mistake is with the exhaust flange gasket to headpipe connection. But, if they follow instructions and use the proper gasket sealer, that should not be a problem either.

    It behooves all of us to fog our motors after each weekends use, before we park the ski for the week. And do not be afraid to rev it up to the rev limiter and blow out any moisture that may be lingering inside your motor after flushing it.

    A two stroke motor can have water in the cases and run at lower rpms without dispelling that water. It takes very high rpms to suck all of the water from the bottom of the cases and process it out of the motor.

    Remember, the exhaust system and muffler hold water too. When you turn your motor off, one exhaust port is always open to the exhaust system. This moisture has a way of finding it's way back into the motor due to condensation, like a teriarium effect, (remember that from 1st grade), So it is possible that you did nothing wrong at all, except not get all of the water out of the exhaust system after use. But, that would not have left a waterline in the cases, just rust on the bearings, which could lead to a bearing failure down the road. I do not think this was your problem with this motor.

    I like to stop on the launch ramp with the ski and trailer on the incline when I blow out my exhaust system after each days' ride. I think it helps to have the muffler lower than the engine when I blow it out. I rev my motor to max rpm two or three times when I blow out the water.

    I do not flush my motor if I have ridden in fresh water, only after salt water rides. The only time I feel it is necessary to flush the motor after using it in fresh water is if I suspect it has sucked up sand or pea gravel and it may have clogged up the brass fittings that are in the cooling system. But, I DO FOG THE MOTOR WITH FOGGING OIL after each trip and before I park the ski for storage. Mecury Marine (Quicksilver) makes a product called Storage Seal, sold at boat stores, that is the best product for fogging that I have found. This stuff coats and protects all of the internal parts during storage periods.

    FYI, The rust in your picture only takes a day or two to accumilate if from salt water in the cases. That is why it is important to fog the motor right after using the boat. Do not wait to fog the motor.

    If you rebuild your own motors, I suggest that you call Randy at Wat-Con and order a pressure test kit. His number is 503 2322026. The kits would more than pay for themselves in one time if there was a problem.

    [ November 08, 2003, 10:40 AM: Message edited by: Bill O'Neal ]
    Bill O'Neal WCM
    <a href="http://www.watercraftmagic.com" target="_blank">www.watercraftmagic.com</a>

  3. #3
    Joined
    Jan 2003
    Posts
    167

    Post

    Bill,

    I don't discount a word you are saying, but assuming that a gasket didn't leak, and I didn't flip the ski (never have) then the only way that I could have introduced water into the ski was during flushing, right? I am very careful to make sure that I have flow on the exhaust system before I introduce any water. I do the same on the back end - water off - engine off. I don't rev the engine to remove the excess water.

    I finished the disassembly this morning. The brearings around the failed crank are bad. The outermost bearing (toward fly) is the worst (which is behind a seal). One other possible scenario is that the crank just failed and that the water entered the cylinder on the tow ride home. Back to gaskets - I actually did resurface one (machine shop) and all others were checked for flatness. Now all that being said could I have screwed up - YEP. My situation for not pursing a SBT engine the first time was core damage ($$$) and wanting to learn more about these engines. Looks like I learned a lesson the hard way.

    Thanks for your post.

    DWT

  4. #4
    Joined
    Feb 2001
    From
    Glendora, Ca.
    Posts
    5,204

    Post

    Read my post again. I edited it and added some information about sleeves too.

    You could be right. The waterline may have formed after the engine blew the rod and made a breech in something, and formed during the down time before you disassembled it. That is a likely senerio.

    Buy the pressure test kit from Randy if you rebuild it again at home. It is very important to know there are no leaks, before you install the motor.

    Good luck.

    [ November 08, 2003, 10:51 AM: Message edited by: Bill O'Neal ]
    Bill O'Neal WCM
    <a href="http://www.watercraftmagic.com" target="_blank">www.watercraftmagic.com</a>

  5. #5
    Joined
    Jan 2003
    Posts
    167

    Post

    Bill,

    Thanks for your help. The worst part about this one is that I debated purchasing the kit when I assembled. I should have done it. I think the crank failure is the most likely mode. Simply because the stain on the crank is so localized (nothing in exhaust or anywhere else. Assuming that that crank rod and bearing got really hot, it could explain the rust. Thanks for the advice for all of us again.

    As for the rest of those reading this post. Failure to test the engine most likely has cost me >$1,000. Don't let the same thing happen to you. I did my best checked each surface and it was not enough ...................

  6. #6
    Joined
    Feb 2001
    From
    Glendora, Ca.
    Posts
    5,204

    Post

    When rebuilding two storke motors without pressure testing the reassembly, you can get lucky some of the time, but not all of the time.
    Bill O'Neal WCM
    <a href="http://www.watercraftmagic.com" target="_blank">www.watercraftmagic.com</a>

  7. #7
    Joined
    Jul 2002
    From
    State College, PA
    Posts
    207

    Post

    Dean,

    I was wondering how thing were going with your ski just a few days ago. It's unfortunate to hear about your problems; I had figured you had everything running great...

    Hope you can get everything straightened out. I guess you now have a winter project lined up [img]smile.gif[/img] .

    [ November 11, 2003, 01:56 PM: Message edited by: cbeastwood ]
    - Craig<br /><br />'04 Baja 342<br />'04 GTX SC<br />'98 GTXL<br />'95 750 ZXI

  8. #8
    Joined
    Apr 2002
    From
    Long Island NY
    Posts
    243

    Post

    I am in the process of rebuilding my 800 motor and was wondering where I could get a pressure tester and for how much?? Does SBT rent them???
    Thanks CHris
    Factory Pipe Spec 2 <br />愛&D Rec Head<br />意ovi 44XR Carburetors<br />FLY Flame Arrestors<br />感rimer Kit/Premix (40/1)<br />愛+D Aquavein Intake <br />Galindo Grips<br />愛+D 85/88 mm Hydro-force Nozzle<br />惹olas XO (16.5/24) Impeller<br />媲each House Sponsons<br />廈ydro-Turf Mats<br />嫂WD Bow Spray Deflector<br />廉armin Etrex GPS (61.5 MPH)

  9. #9
    Joined
    Jan 2003
    Posts
    167

    Post

    Craig,

    Actually, I finally got the carb tuning just perfect when she fried. OH well!

    DWT

  10. #10
    Joined
    Feb 2001
    From
    Glendora, Ca.
    Posts
    5,204

    Post

    97GSX,

    You can get one from Randy at Wat Con, 503-2322026
    Bill O'Neal WCM
    <a href="http://www.watercraftmagic.com" target="_blank">www.watercraftmagic.com</a>

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