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  1. #1

    Cool So many questions I don't know where to start!

    OK. Lets start with the rig. I have a 95 slt 750. My dad bought it as a toy and it only had like 50 hours on it. The first day I get on it, and I'm not impressed at all. Well, come to find out, it had a hole in the mag piston (#1). great.... replace the piston, fresh rings the works. Runs great! Now for a 3 seater, I'm impressed. Replace the stock fuel pump with a 3 output and replaced all of the fuel lines with the clear blue tubing. Other than that, it's stock.
    Now comes the questions. I have read almost every post on here that has to do with upgrades and making more power / speed, which is what I am after, top speed. Right now, I have had a top speed of 48.4 by the speedo. Don't have a GPS reading yet. Everything I have read says that the top speed should be anywhere from 50 - 55? WTF? I have had lots of thoughts about drag. I keep it in the water and it builds up scum, which drags it down to 39 - 40. Now if that little bit of stuff brings it down that much, what about all the scraps and dings? What about the corrosion on the ride plate and intake grate? They feel like 20 grit sand paper. I was thinking about taking 400 grit wetsand to it while in the water and see if that helps. Anyways, I have a ton more questions, but I want to stretch them out a little to let all of your input absorb into my tiny little brain! I guess for this one, what are your hull / ride plate suggestions for speed? Thanks ahead of time.


  2. #2
    She likes the bike. But the ski gets her wet!!!! xlint89's Avatar
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    Welcome to the Hulk Jason.

    Many things to be done with these, how much you want to spend is up to you....

    Your speed seems a little low, what's your RPM at?

    Impeller and/or stator damage will hinder performance.

    For a cheap upgrade, try installing a pump wedge to get the nose up and out of the water.

    Drag is a concern, but I'm willing to bet something else is off. Impeller to wear ring clearance limit is .020. Anything more than that, and you'll lose pump pressure.

    What's the compression of the cylinders?

  3. #3
    Quote Originally Posted by xlint89 View Post
    Welcome to the Hulk Jason.

    Many things to be done with these, how much you want to spend is up to you....

    Your speed seems a little low, what's your RPM at? 6120 - 6240 in chop 6180 in glass.

    Impeller and/or stator damage will hinder performance.

    For a cheap upgrade, try installing a pump wedge to get the nose up and out of the water.

    Drag is a concern, but I'm willing to bet something else is off. Impeller to wear ring clearance limit is .020. Anything more than that, and you'll lose pump pressure.

    What's the compression of the cylinders? 150 across the board.
    Haven't checked the impeller clearance yet. Never even thought about that. And as for the wedge, To hit top speed, I do have to lean way back and crouch to get out of the wind. Thanks.

  4. #4
    I was reading about different vein setups as well. I think stock is a four vein? I have yet to rip the pump out or anything that really involves me wanting to completely redo everything with aftermarket. What is the purpose of this? Frm what I understand, it's to keep back pressure on the impeller. Seem to reason that this would make a big difference in performance.

    What about triple pipes? How much of a difference does that make other than shedding some pounds compared to the 50 lbs stock manifold?

  5. #5
    Click avatar for tech links/info, donation request K447's Avatar
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    Quote Originally Posted by Jason Moorhead View Post
    I was reading about different vane setups as well.
    I think stock is a four vane?
    On the early and non-performance models (1994 onwards), stock was a five vane jet pump stator made from aluminum.
    Then two 6 vane stainless steel stators were produced (Skat-Trak and Asian?), which provided better performance than the 5 vane.
    Also available are 8 and 12 vane SS stators, intended for better hook up in rough water operation.


    ...What is the purpose of this?...
    The fixed blade pump stator compensates for the rotational torque of the spinning impeller, preventing the PWC from wanting to twist over as the engine power increases. It also straightens out the water stream, providing a more effective jet thrust.

    What about triple pipes?
    How much of a difference does that make other than shedding some pounds compared to the 50 lbs stock manifold?
    Almost all Polaris impellers are three bladed, but there were some four bladed ones in the early days.

    The triple pipes can really boost output power, but require re-tuning or upgrading the carburetors.

    Weight wise, those long triple pipes have extensive water jackets, which does add some wet weight.

    Overall, the pipes act like a supercharger for a 2-stroke engine, but with a power curve more like a turbo charger.

  6. #6
    Thanks! So is the weight increase worth the power, or does it just equal back out?

  7. #7
    ShaneG's Avatar
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    Tripple pipe advantages far out weigh any weight gain; the HP gains are incredible. Problem is finding them for the SL hulls. As K447 eluded to, tuning of the motor is not easy with different jetting and mixture screw adjustments to make sure you don't lean it out and burn it down.

  8. #8
    Thanks guys! Very good info. I was also looking into putting pissers on it. Read alot on it and not only does it look cool, but it is also very useful. If running a single, I get to use no less than 3/4', but for triple 3 3/8" will work? Don't want to cause flow problems, but I want to get some good distance with it too.

  9. #9
    ShaneG's Avatar
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    I know of one set of tripples for the SL hulls, but I think the guy wants like $700 complete set up pretty much new in a box. Getting them may take a little while though as he just moved and is sorting out and unpacking.

  10. #10
    Bottom line: it's a 750. your average SLT750 is going to go around 45mph, not 50-55. My bro had one. I had a SLT780, average speed 46-47. I would not waste too much money on it trying to get it to go a speed that's not attainable. money goes quick on these skiis, and you are better off saving what you need, along with selling it and getting one with a bigger motor. For instance, let's say you save $1000, sell your SLT for $1500, find a SLTX1050 for $2500. Bam! you got your 55mph and bigger motor. Enjoy the ski you got for what it is. Want much more and just get one that already does it. Want to tweek yours a little, this is the place to do it.
    JOE

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