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  1. #1

    Polaris MSX 140 top end rebuild

    I have recently purchased (2) 2003 Polaris MSX 140s. The one was running but had low compression (90) in the #1 cylinder. The other was not running at all and the previous owner had disassembled the #1 in that ski. He had blown the piston and rings and gave up trying to repair it. I bought a new OEM cylinder along with new rings and piston, rebuilt the ski and was following the manufacturers break in procedure. We ran it 30 minutes at low rpm then let it cool for 30 minutes. We repeated for about 4 hours and the ski came to a complete stop. We checked compression on all 3 cylinders. 2 & 3 were 120 and zero compression on #1. Pulled it apart again and the piston and rings were destroyed. Read some good advice on the fuel pressure regulator and sure enough it was in the bottom of the fuel tank. We fixed that and waited on a new cylinder, piston, rings to arrive. New parts came last night and when we went to install the new cylinder, piston, rings and wrist pin bearing we noticed the entire block had filled with gas/oil. We tried pumping it out but seemed to keep getting in. We are leery to put it back together because this doesn’t seem right. Any advice would be appreciated. Thanks!


  2. #2
    Click avatar for tech links/info K447's Avatar
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    Welcome.

    Is the engine ‘filled’ with gasoline or with oil?

    How are you attempting to ‘pump it out’?

    If the front (number 1 cylinder) crankcase section has been sitting with a lot of liquid inside, the flywheel housing may also have liquid inside. Seeped through the front crankshaft seal. If so, the flywheel housing must also be drained and dried.

    If you have not found it yet, click here for lots of useful Polaris PWC info.
    http://polarispwcknowledge.shorturl....t-things-to-do

  3. #3
    Hello and thanks for the reply. The engine is filled with both gas and oil (mix). I have a diaphragm pump that I used to draw out as much as I could. For a minute I thought maybe when we put the cover on it had pulled back on the throttle and kept it open but I doubt that would allow the fuel to flow into the engine. Is it safe to say this ski should not be started until all of it has been removed? It's like the engine got flooded and needs cleared out.

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    Quote Originally Posted by jroof View Post
    ... The engine is filled with both gas and oil (mix). ...

    Is it safe to say this ski should not be started until all of it has been removed? ...
    Is the fluid MOSTLY gasoline or MOSTLY oil?

    What the (bulk of) fluid is will tell us how it might have gotten in there, which then tells us what needs to be fixed.

    Do not attempt to crank the engine until this gets sorted out.

  5. #5
    It is mostly gasoline but mixed with the oil in what appears to be about the correct ratio. Since it's oil injected it's hard to tell exactly but the gasoline is blue in color from the oil. I use the Polaris VES Synthetic.

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    Quote Originally Posted by jroof View Post
    It is mostly gasoline but mixed with the oil in what appears to be about the correct ratio. Since it's oil injected it's hard to tell exactly but the gasoline is blue in color from the oil. I use the Polaris VES Synthetic.
    That Polaris blue oil dye is pretty strong. I have seen hulls stained blue from oil leaks.

    Normally the only way gasoline could accumulate inside a Ficht engine would be if a fuel injector was somehow stuck open.

    Stuck open Ficht fuel injectors are rare. Possible, but not at all common.

    The crankcase sections are connected via a labyrinth crankshaft seal, so liquid accumulation in any one cylinder can seep into the others over time. And might also seep into the flywheel housing.

  7. #7
    It's really strange because we had both skis apart replacing the same #1 cylinder. The cylinders and pistons were out and the only thing left were the connecting rods. They both sat for 4 days waiting on parts. The one ski was perfectly dry while the other filled to the top of the block with the gas/oil.

    We had clean rags stuffed in both to keep dirt out and the rag was soaked as well. The injectors weren't even attached and the batteries were disconnected.

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    Quote Originally Posted by jroof View Post
    It's really strange because we had both skis apart replacing the same #1 cylinder. The cylinders and pistons were out and the only thing left were the connecting rods.

    They both sat for 4 days waiting on parts. The one ski was perfectly dry while the other filled to the top of the block with the gas/oil.

    We had clean rags stuffed in both to keep dirt out and the rag was soaked as well. The injectors weren't even attached ...
    Were the fuel injectors just laying on top of the engine?

  9. #9
    They were pulled and laying on top but not over the open cylinder heads. The injectors were dry and didn't appear to be allowing gas/oil out.

  10. #10
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    Quote Originally Posted by jroof View Post
    They were pulled and laying on top but not over the open cylinder heads. The injectors were dry and didn't appear to be allowing gas/oil out.
    Is the oil tank nearly drained empty? The oil tank only holds maybe five liters, if oil was flowing into the engine enough to ‘fill it’ then the oil level would be noticeably lower.

    For gasoline to be flowing into the engine from the fuel tank, it would have to somehow get out of the fuel lines and into the engine itself. Only the fuel injectors and the hoses to them carry liquid fuel. Really simple fuel hose layout.

    If the liquid is mostly water, that would also be strange for an engine just sitting in a dry hull on a trailer.

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