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  1. #1

    a few questions 98 SLTH 700 twin(red)

    Just took out the "new to me" ski yesterday for the first time... I had already put a new battery (reading 15v on the mfd the whole time), and changed all the grey temco fuel line i could see.. ( didnt actually look too bad inside them) drained the seperator, and installed a inline fuel filter.. Ski seemed to have good power but after a few minutes i would notice that it would seem to develop a "surge" if i was cruising along at say 5700 rpm it would drop to aroud 5000-5200 for a little then take back off again... it would do this randomly on and off.. I tried applying the choke when it was doing this to see if a little extra fuel would change it, and no difference.. Plugs look nice and dark tan/brown (almost rich).. SO i am wondering could it still be a fuel issue, or am I most likley looking at a stator or CDI issue? was going to try fresh fuel and new plugs and see if any difference.. was about 2 gal of old fuel in it and I put 4 gal of fresh in before i went out... same plugs were in it from last season...

    Also is it normal to have some water in the hull? seemed to be 2 or 3 inches in spots, but not high enough for the pump to pick up... was below the drain plugs in the back, but still a decent amount... couldnt tell where it was coming in from...

    Thanks for any ideas or help...

  2. #2
    Banned User
    Join Date
    Jun 2010
    Milwaukee WI
    Does it have the original or updated ignition? Have the carbs been cleaned/checked/rebuilt? I dont believe this ski came with an in line fuel filter. There is a fine mesh screen filter in the water separator. I just rebuilt a 99 SLTH so im very familiar with this particular ski.

  3. #3
    Click avatar for tech links/info, donation request K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada

    Lots of useful info can be found through my signature links.

    Full carburetor rebuild should be high on your list of things to do.

    Water in the hull, look for where it is coming in. Check the through-hull seals at the drive shaft, the speedometer pitot hose under the drive shaft. Also check the cooling hoses for leaks.

    When the hull is level or nose high on the trailer the water should drain out the rear drain holes. Make sure those are not leaking water when in place. If you have the old style removable rubber plugs they can be replaced with the newer captive style.

  4. #4
    Polarisitis loonatik's Avatar
    Join Date
    May 2010
    Tampa, FL
    Drop in RPM could possibly mean fuel starvation. You didn't mention anything about the carbs so I'd 2nd that with Bryan, they need to be gone thru.

    Piston wash reading is more reliable and preferred over spark plug reading. Proper plug reading is done with fresh plugs and killing engine at full speed. You may find it in Tech Tips section, or look at this link:

    Anytime a leak is suspected, first place to check is the "thru hull drive shaft coupler". The seals are probably bad.

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