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  1. #1

    Cylinder temps/ carb rebuild??

    I purchased a used 94 750SL to replace the one I blew the motor on last year. I've read lots on these 750's. I have installed a shutoff valve on the water inlet so it won't flood the engine, if I have to get towed. I've installed new fuel lines and I'm about to install my triple fuel pump. I took it out for a few test rides before I switched the fuel pump.

    I took my temp gun and kept a very close eye on the cylinder temps. I got readings between 115F and 130F right at the spark plug holes. I also put the temp gun right up to the cyliner head and got very similar readings. The hottest reading I got was 133F. The ski ran great. NO WOT, only 1/2 to 3/4 throttle max (till I get the triple fuel pump installed).

    Should I rebuild the carbs, even if they aren't giving me problems? I was just thinking about that old saying "Don't fix it, if it ain't broke". Maybe I should rebuild these carbs to make sure it doesn't break? The temp seems to be fine (Correct me if I'm wrong), so I thought I would ask some PRO's

  2. #2
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Campbell, Ca.
    If the carbs have been sitting and the fuel is/was old, don't risk the damage that may occur if the carbs are dirty or the fuel system is restricted. Remember WOT is where you'll burn her down.
    1 vote hear for a carb cleaning.

  3. #3
    I agree with AL !!!! Vote #2 Clean and inspect the carbs

  4. #4
    There was no fuel in the gas tank or fuel lines when I got the ski. It seemed really clean. It did have a re-shoe that had regular silicone, and a sloppy job. BUT No cavitation so far. I've put fresh fuel in and topped off the oil tank. Has anyone else done the temp gun readings on a 750SL? How do the temps seem?
    Last edited by polaris 750SL; 07-27-2008 at 04:36 PM.

  5. #5
    HI! my temp gun readingd are anywhere from 120 to 170 but I try to run mine safe

  6. #6

    What temp sets off MFD Guage?

    What temp sets off MFD Guage on the 1994 750??

  7. #7
    I don't remember off hand but it is in the pdf manual in the tech section

  8. #8
    Click avatar for tech links/info K447's Avatar
    Join Date
    Jul 2007
    near Toronto, Canada
    Quote Originally Posted by polaris 750SL View Post
    What temp sets off MFD gauge on the 1994 750??
    Quote Originally Posted by ZMANN View Post
    I don't remember off hand but it is in the PDF manual in the tech section
    Fuji engine overheat HOT temp warning sensor is 180F, domestic Polaris engines 160F.

    Page 436 in the 1992-1998 Service Manual.

  9. #9

    MFD Hot sensor

    The MFD light blinked and I pulled the cord right away. The MFD said HOT. I checked the cylinder heads, which were 125-135F, and the exhaust was 102F. I let the ski cool for about 10 minutes. I also reached under the ski and removed some grass from the grate. I rode it back to the dock @ 1/2 throttle, about 4 minutes and the light did not come on. If you shut down the motor right away, is there any damage caused? What can I check?

  10. #10
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Campbell, Ca.
    Check compression and see how you look. You may still have cylinder wall damage (I doubt) so you'd need to pull the heads and verify.

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