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  1. #1
    6y5kwjm's Avatar
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    00 SUV rpm problem

    I hope someone can help me out . I was riding one day and my rpm goes from 5700 to 4500. We check the carb, then the reeds and found the middle was opened and number #3 also needed to be replaced.


    Got a set of SBT reeds and installed them, also replaced plugs and fuel filter. Bolted everyting back up and still cant get past 4500RPM. The W. Temp sensor is ok so i dont think that limiting it.

    Funny though if i put it in reverse then 1/4 throttle then a WOT it runs up to 7000+ RPM. When i again go forward it peaks at 4500.

    Any suggestions?


    Thanks,
    Andrew

    '97 Wave Venture 1100
    '99 SUV 1200


  2. #2
    Moderator OsideBill's Avatar
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    Not sure what to say, The RPM should be about 6800 and up, this sounds way off. are you sure you do not have something restricting your impeller? or maybe a bearing problem in the pump.

  3. #3
    6y5kwjm's Avatar
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    Impella is clear, but as i mention if I go into reverse after a few hits on the throttle it runs up to the max on the rpm meter.

    When its out of water the WOT is also at 8000rpm just under water load it stops at 4500.

  4. #4
    Moderator OsideBill's Avatar
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    I can't explain the reverse phenomenon, might be you just need some PM. Check compression of the cylinders first this thread explains how. http://greenhulk.net/forums/showthread.php?t=71862

    What did your spark plugs look like? maybe a carb rebuild is in order how many hours on them? are you getting good fuel flow through the fuel selector switch?

  5. #5
    Dave Sharp dav_dman's Avatar
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    agree..i bet you have about 50 lbs comp in one cyl.

  6. #6
    this is whacky! only a bucket drops for reverse no moving parts change direction

  7. #7
    cyrillefrenchy's Avatar
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    these suvs are very heavy, they don't respond quickly on reverse and when you are on reverse , the water thrust you throw towards the intake grate is half water and half air bubbles, makes the jet unit to cavitate very easily, making the rpm going higher on reverse than forward.when they start cavitating they don't stop unless you go back to forward.
    this is my version, that's what mine does.
    cyrillefrenchy

  8. #8
    That makes sense! I never tried gunning anything in reverse! so back to compression test

  9. #9
    6y5kwjm's Avatar
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    Wow, just did the compression test nothing on the center cylinder. Took the head off to find a hole on the exhaust side. Even scared the block. I want to bore the cylinder about 1mm. Should i take the whole engine out and check for fragments in the crankcase?

    Being in Jamaica not excaclt readily available. Hope to do a one day shiiping and get someone to bring it down piston and rigns for Saturday Morning. Is there anything else i may need to get or check??

  10. #10
    cyrillefrenchy's Avatar
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    piston melted on the exhaust side mean lean condition, right?
    for me the right way to do the job is to take the engine apart, check crankshaft very well (sometime some debris are falling in the case and they damage the rods bearings ),replace crank seals , take your time and use a good sealant to put the crankcase together,replace the 3 pistons , hone or rebore the cylinders if needed according to the size of pistons and go thru a complete carburator rebuild with 3 new rebuild kit and replace all included in the kits.everything should work like new again.
    now if you want to go cheap, just take cylinders off, replace only one piston, hone or rebore the bad hole, carb rebuild and go but the risk is big, you may have to do it again soon.be carefull, these engines like to throw rods thru the case .
    good luck and keep posting.
    cyrillefrenchy

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