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  1. #1

    2013 XLT 1200-Rough idle, rear cyl warmer to touch..?

    Recently rebuilt carbs, replaced fuel lines and fuel filter, drained fuel and replaced with new. Replaced oil lines from check valves up and primed with oil before connecting to carbs. I finally got all back together today and test fired. This is the first time that I have heard the thing run, as I just recently bought from my friend. Needed to pull plugs 3 times as I had poured some oil down the cylinders prior to completing compression test when I first picked the ski up. Previous owner had also stored with oil in cylinders, so needless to say there was a lot of smoke.

    My issue is that the thing in idling really rough on trailer. It almost sounds like a miss. After just having rebuilt the carbs I wanted to run it on the trailer in the driveway with the hose first before even considering a trip to the river. The other thing that concerns me is that the rear cylinder is warmer than the center and front. Pulling the plugs I noted that the front and center have a little bit of oil on them whereas the rear doesn't seem to have as much. All three cylinders appear to have good spark. I added about an inch to the length of the oil lines when I replaced to hopefully mitigate the issue that you hear of - shrinking lines that eventually pull of the carbs and seize up pistons.

    I can't see how this would be an oil injection issue since the lines where all primed the same way.

    Any thoughts?
    Last edited by tunelowplayhard; 09-08-2013 at 07:52 AM.


  2. #2
    Are you running premix or the oil Pump?
    Oil Line could have popped off.
    Check compression on all 3, if you haven't since you bought it, and make sure that there isn't more than a 10% difference between them.

  3. #3
    Quote Originally Posted by tejhummer View Post
    Are you running premix or the oil Pump?
    Oil Line could have popped off.
    Check compression on all 3, if you haven't since you bought it, and make sure that there isn't more than a 10% difference between them.
    As per above, still running the oil injection. I replaced the lines from the check valves to the carbs because the factory lines where hard on the ends and I wasn't sure if I would have enough slack to cut the ends. Also, noting what I've read here on the forums, the primary reason for the lines popping off seems to be that they shrink (linearly) as they get old and pull of the carbs. I primed the lines by sticking the end in the onboard oil container and pulling a vacuum on them. They were all filled to about 1/2 inch from the carbs when I put them on. Prior to starting I also turned the motor over with the plugs out and the throttle pulled with thought that the pump would fill the lines that last half of an inch. Regardless, there was a lot of oil int he cylinders as the previous owner had stored it with a tsp or so of oil in the cylinders and I too had dumped about a tsp or more of oil down the cylinders prior to turning over to do my compression tests. So needless to say there was a lot of oil in the motor. I had to remove the brand new plugs 3 times and clean off oil before it would finally fire.

    Looking through the forums it sounds like these engines are known for having a bit of a rough idle and I can live with that. My concern is the 3rd cylinder being warmer than the others. I'm looking at it this way - it's either warmer because it's lien or it's not getting oil, right? I guess I could pull the mid-exhaust to see if the oil is up to the carb..?

    All the carbs passed the pop-off tests so I can't see how this would be the issue. I have brand new gaskets from base to rack and and a new gasket between the rack and the plastic silencer plate. The gasket on the manifold itself stayed behind when I pulled the carbs and it looks fine. This doesn't sound like an air problem to me. Btw, it revs up fine too - no concernable bog on the trailer/stand on the hose but I don't want to put it in the water yet until I have some clarity on this warm 3rd cylinder.

  4. #4
    mudslanger's Avatar
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    Since you have worked on the oil injection you should run premix for at least one tank to make sure everything is working properly. Also have you pulled the plug wires off 1 at a time wile it was running to make sure it is running on all cylinders. When you say the rear cylinder is hotter than the 2 front cylinders just how much. Is it so hot you can't hold your hand on it? You may need to put it in the water if it is running on all cylinders and test ride it.

  5. #5
    Quote Originally Posted by mudslanger View Post
    Since you have worked on the oil injection you should run premix for at least one tank to make sure everything is working properly. Also have you pulled the plug wires off 1 at a time wile it was running to make sure it is running on all cylinders. When you say the rear cylinder is hotter than the 2 front cylinders just how much. Is it so hot you can't hold your hand on it? You may need to put it in the water if it is running on all cylinders and test ride it.
    Warmer meaning 1 and 2 feel cool to the touch while 3 is warm. Not to the point where I can't hold my hand to it but noticeably warmer.

    One other question with regards to pilot water hoses. I noted that one side was dumping more water than the other. Is this normal or should same amount be coming out of both?

  6. #6
    mudslanger's Avatar
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    The amount of water coming out of the rear of the ski will not be the same.

  7. #7
    UPDATE: Put the ski in the water yesterday. I'm happy to report that the cylinder temperatures are all pretty consistent now. From an engine performance perspective, it seems to be running okay. Running on the garden hose for the initial tests appeared to be contributing to my initial concerns and I will continue to monitor.

    On another note, I have a massive cavitation issue from a start. It doesn't "hook up" at all out of the hole. The engine just revs. I know that there are multiple posts about pump seal kits and intake grates, but I would like to understand why the need arises to take these actions. Certainly when the machine was new it didn't cavitate the way it is now - so what changes to cause the issue?

    Based on what I've read about cavitation in general, whether it be jet pumps or industrial pumps, smooth surfaces are a must; however, what is not smooth enough? See pic. Could this be causing my issue? Those blotches are salt scale. Would this be enough to create the cavitation as the water flows past?

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    I replaced the impeller with an identical version that I purchased used from ebay. The wear ring was also replaced off a fresh water ski and the tolerances are within specification. I used the 3M 4200 sealant as per numerous recommendations found on this site, applying a nice beed. I can see that some has been squeezed out so I know I have enough applied. Once you ease the thing onto plane, you can get about 45MPH out of it on the speedo. Pulling the throttle out more aggressively just results in more revving and no additional speed increase.

    I'm inclined to replace the intake great with aftermarket rather than replacing with stock, but I would like to know if the pictures support the cause of my issue.

  8. #8
    mudslanger's Avatar
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    To answer your question no the pits and scale are not causing the cavitation. But you should go to the aftermarket grate. Normally what causes the seal to go out on the pump shoe is water coming into the pump tunnel. When the ski is moving at normal speeds the water pressure in the pump tunnel is very low and at times a negative pressure. But when you let off the throttle wile the ski is moving at normal speeds the pressure goes from very Low to very high and if you are going fast the pressure is even more. This high pressure in the pump tunnel is pushing on the pump shoe seal and over time blows out this seal. The improvement is to fill all the voids in the pump shoe and replace the seal with new or 5200 or other sealer.
    Hope this helps.

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