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'93 SL750 Jetting

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  • '93 SL750 Jetting

    I rebuilt my sl750 over the winter, and broke it in on a tank of gas in the past few weekends. I did the plug chop test 3 times. First time the hi-speed screws were turned out 1 full turn. Porcelain was white. I turned it out 1.75 turns, and the porcelain was white. I turned it out a full 2.5 turns, and still the porcelain was white. I skipped riding the sl for the rest of the day for fear that I would blow it up.

    Obviously it's running lean. I checked the Polaris manual for a '93 sl750 and the main jet is a #78 I believe (from memory). I checked a '95 sl750 and I believe the main jet is a #90. A '95 sl780 is a #105 main jet. The first couple years the sl750 had problems due to lean conditions either caused by the fuel pump and now I'm also suspecting the jetting as well. Because I bored my motor out 0.020" (755cc's vs. 744cc's stock) I know for a fact I'm going to need more fuel.

    My plan of attack is by three sets of jets, #90's, #95's, and #100's. Do you think the #95's will be a good baseline for jetting? I should be able to tune it from there with the hi-speed screws, but if not, I could go either richer or leaner with the other jets.

    Has anyone had experience like this with the sl750? Thoughts? Thanks for your time.

    Doug

  • #2
    Re: '93 SL750 Jetting

    if you still have the stock flame arrestor installed log onto parker yamaha. they sell a genuine polaris updated flame arrester kit for about 50 bucks. nice new flame arrestor, adapters with new oil lines, larger jets for such, new screws etc. really cheap for what you get. check it out. make sure your fuel line restrictor is in place also. sometimes people replace the fuel line with new not knowing there is a restrictor in the fuel line. good luck. kevin

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    • #3
      Re: '93 SL750 Jetting

      Originally posted by Frisbee
      if you still have the stock flame arrestor installed log onto parker yamaha. they sell a genuine polaris updated flame arrester kit for about 50 bucks. nice new flame arrestor, adapters with new oil lines, larger jets for such, new screws etc. really cheap for what you get. check it out. make sure your fuel line restrictor is in place also. sometimes people replace the fuel line with new not knowing there is a restrictor in the fuel line. good luck. kevin
      I'm sure I could go that route, but that's not going to fix my problem. I would like to get it dialed in first before I go adding aftermarket parts.

      Currently, I do have the triple outlet pump and the stock flame arrestor installed. I also have the fuel line restrictor in place (0.100" hole drilled in bolt). I'm pretty sure it's a jetting issue at this point.

      Doug

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