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  1. #1

    94' sl750 top speed problem

    first off this forum has been the bible for me the last couple of months....guys i have problem that showed up yesterday on the lake. I can't go really above 35. The pto cylinder burned a hole in it few months back. that's all fixed. New rod kit and piston installed. with a used std bore pto cylinder. updated 3 outlet pump. ran new clear blue fuel lines. installed a restrictor since it was missing one. and that's prob why she popped. installed a new fuel selector and installed a oil block off plate and installed a 44ohm resistor inside the elec box to spoof the mdf. there isn't a oil level reading now on the mdf...not sure why. i thought it was supposed to show full. new boysen reeds and i installed a new seat n needle on the pto carb cuz it got damaged when i tried removing the carb screws. rebuilt the pto carb and checked the pop off pressure for good meaure... all within spec. the machine has been on the lake about 5 times now with around 60miles put on it, it starts and runs like a champ. went 50 no problem...launches real nice. absolutely no flaws. yesterday i took it out and would only hit like 30-35. so i changed the plugs thinking it was fouled from a rich mixture from break in. was running 32:1 for break in and now its running 40:1. new plugs did not make a difference. so i read the new plugs. the mag is brown whiteish. the cen is perfectly tan and the rear is brown with some black. did a compression test on it and looks to be all good. performed a spark test and all looks good. used a cam to check piston wash and looks perfect in the cylinders. Im really handy with motors and have ridden dirtbikes for 10 years. I have rebuilt many motors and detail and tech savvy. I own a sl750 repair manual and have been following it for the repairs.


    I was reading about the machine going into limp mode and limiting the power output. how do i know if the machine is in limp mode. the mdf does not blink when riding or shows any problem.


    1800prm idle in the water now. It used to do 2000 in the water after the rebuild
    5100 max rpm now. it was well over 6000 after the rebuild
    30-35 max speed now. did 50 easily after the rebuild
    when pulling choke at full throttle it falls on its face

    It almost feels there isn't any more throttle cable left to pull but i checked that and its all tight when pressing on the throttle and there isn't any slack.

    I think a gremlin is messing with me. What do you guys think it is.

  2. #2
    I'm addicted to Polaris PWC ghostinstallations's Avatar
    Join Date
    Aug 2011
    Rochester, New York
    Piston wash?

  3. #3
    looks good besides some black in some spots. there are patches of silver. checked it with a cam

  4. #4
    BlueFishCrisis's Avatar
    Join Date
    Aug 2011
    Medina, Ohio, United States
    Have you recently check your reed condition?

  5. #5
    reeds are good. Ran ski on hose and hit 6500rpm. Adjusted the high mix screw on mag to richen er up a bit and leaned out the pto one. Im stumped. Thing feels like there is a fat chick on the back lol. Im gonma take er out again n read the mag plug

  6. #6
    Update. richened the mag cylinder 1/4 turn n leaned out the pto 1/4 turn. Runs like a champ. Max rpm 6350 and top speed of 50. The idle is 1800 with idle adjustment screw not even touching the plate. Thanks everyone for your input

  7. #7
    I had the same problem for a year. And no one could say. What it was. Here one of the reeve values had a hole in it

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