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  1. #1

    Problems with XLT 1200

    I have read hundreds of threads online but cant find my solution.

    Ski starts up promptly every time and idles without problem. I can usually make it 30-45 minutes of riding having no issues then suddenly the motor starts to bog down. It wont die and you can pull throttle wide open and it will keep running but sounds very muffled and boggy. When this happens, ski wont accelerate much at all and if I keep pushing it slowly, it will get up on plane but no where near top speed and I can tell by sound of engine that it isnt right.

    What Ive done so far:

    Removed and cleaned power valves which were very full of carbon build up and gunk. Reinstalled, using waveeater clips and couplers.

    Replaced servo motor because it wasnt operating.

    Removed oil pump and coverted to premix (40:1)

    Crabs were supposedly cleaned 2 years ago and ski sat with no fuel in carbs during this time because of the bogging issue and previous owner didnt mess with it.

    Compression is 110 on all 3 cylinders. Ski has 130 hours and is original motor. D-plate and chip was installed many years ago.

    Water is flowing out pee hole and Im not getting any alarms or indicators on display.

    I did a hot shutdown today and immediately pulled spark plugs. Front cylinder looked pretty normal and had tiny amount of smoke coming from plug hole, middle plug was very dry and had more smoke coming from plug hole and rear plug was more wet than other two and no smoke coming from plug hole.

    I noticed it smelled like gas when I pulled the seat, not sure if it was fumes from tank or leaking somewhere?

    Im thinking about pulling carbs and rebuilding myself but cant figure out why ski would run great for 30-45 min then bog out on me. Sometimes it bogs much sooner but Ive also gone a full hour with no issues.

    The inconsistency is whats got me confused.

    Any suggestions? Thanks in advance

  2. #2

    Join Date
    Feb 2010
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    I would definitely consider rebuilding the carburetors with oem parts and adjust the high/low screws accordingly. Your adjustments and parts may vary slightly depending upon what's been done to the jetski. There are "recipes" on this sight for rebuild specs, or have one of the folks on here do it for you professionally. michael


    Quote Originally Posted by Pullen724 View Post
    I have read hundreds of threads online but cant find my solution.

    Ski starts up promptly every time and idles without problem. I can usually make it 30-45 minutes of riding having no issues then suddenly the motor starts to bog down. It wont die and you can pull throttle wide open and it will keep running but sounds very muffled and boggy. When this happens, ski wont accelerate much at all and if I keep pushing it slowly, it will get up on plane but no where near top speed and I can tell by sound of engine that it isnt right.

    What Ive done so far:

    Removed and cleaned power valves which were very full of carbon build up and gunk. Reinstalled, using waveeater clips and couplers.

    Replaced servo motor because it wasnt operating.

    Removed oil pump and coverted to premix (40:1)

    Crabs were supposedly cleaned 2 years ago and ski sat with no fuel in carbs during this time because of the bogging issue and previous owner didnt mess with it.

    Compression is 110 on all 3 cylinders. Ski has 130 hours and is original motor. D-plate and chip was installed many years ago.

    Water is flowing out pee hole and Im not getting any alarms or indicators on display.

    I did a hot shutdown today and immediately pulled spark plugs. Front cylinder looked pretty normal and had tiny amount of smoke coming from plug hole, middle plug was very dry and had more smoke coming from plug hole and rear plug was more wet than other two and no smoke coming from plug hole.

    I noticed it smelled like gas when I pulled the seat, not sure if it was fumes from tank or leaking somewhere?

    Im thinking about pulling carbs and rebuilding myself but cant figure out why ski would run great for 30-45 min then bog out on me. Sometimes it bogs much sooner but Ive also gone a full hour with no issues.

    The inconsistency is whats got me confused.

    Any suggestions? Thanks in advance

  3. #3

    Join Date
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    I think I remember some people saying it can be that there is a vacuum forming in the gas tank. I'm not 100% sure but search around for bogging down and the gastank / gas selector.

  4. #4
    jeffg426690's Avatar
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    Your probably due for a carb rebuild (I would if it was my ski, especially if it sat for two yrs). Mikuni kits only - no aftermarket. Do fuel return mod while your at it (in the How-to's on this site in this section)

    Fuel circuit:
    check valve on the tank vent hose (that's what can create vacuum that Mitch was talking about) - remove and inspect it by blowing through it, its a one-way valve. Arrow points towards the tank to let air into tank.
    Fuel selector could be gummed up (temporarily bypass to check if this is the prob)
    Fuel filter could be a culprit.

    Those are some first things to check...

  5. #5
    dockwalker's Avatar
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    Check all fuel lines since you smell gas.Might get launched off the line,faster than you want.Check fuel pickup tube and flapper valve.


  6. #6
    Ive read the threads on the fuel flapper in the tank and plan on checking that tomorrow. Im confused though because some say they just remove it and others say the add some clunk filter piece. Which is necessary/best if my flapper is messed up?

    I checked all fuel lines and dont see any fuel leaking. Has a brand new fuel filter too.

    If it is carbs, or the flapper for that matter, why isnt consistent? Thats whats confusing me.

  7. #7
    jeffg426690's Avatar
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    Yank the flapper off, that's all there is to that.
    Your fuel vent check valve could be the gremlin and would be the first thing I checked. Its purpose is to allow air into the tank to allow for fuel consumption without creating a vacuum (negative pressure) in the fuel system as the volume of fuel displacement in the tank changes (lowers) while the motor is running. Being a one-way valve, it also is part of what maintains the positive pressure in the fuel circuit that is created by the fuel pumps in your carbs while running. If it is stuck closed it will, over time while your running, create a vacuum that is typically most noticeable when the carbs are trying to draw more fuel.
    The fuel smell could be from the needles and seats in your carbs being worn and allowing fuel to leak. Could be other things too, but that's a likely suspect from it sitting for a long time. The viton tips of the needles leak...
    Again, I'd be going through the carbs and rebuilding them without much delay. You don't want to learn the hard way that your running lean...

  8. #8

    This is my flapper.this is how it looked. Likely my culprit? The check valve/one way vent is working properly.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Last edited by Pullen724; 08-04-2018 at 06:47 AM. Reason: Typo

  9. #9
    butterbean_29512's Avatar
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    If you smell gas you have a leak somewhere. A leak while the engine is shutdown turns into a air leak INTO the fuel system with the engine running, which starves the engine while running, esp. at WOT.

  10. #10
    Update:

    Rebuilt carbs, replaced all fuel lines and reassembled. I tested it today and it ran about 95% better (no bogging at heavier throttle). Only problem I noticed was occassionally it would slightly bog when accelerating off idle, depending on how quick or slow I pulled throttle. It pushed right through the bog but I need to figure out what setting to adjust to clear that and I need to make sure Im not running too lean. Im not sure if the attached pic of plugs is adequate to help me out with deternining lean/rich.

    The carb settings cant be adjusted without removing the exhaust which is a pain. Just tryinv to get this thing right so I can have a dependable ski.

    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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