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    "500ss spark plugs"

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    • Member since
      November, 2008
    "500ss spark plugs"
    Posted by jdmxz on Monday, September 28, 2009 6:26 AM

    I am looking for a little help. Do to pressure from EPA, SKI-DOO has leaned out the carbs and advanced the timing for the 2008 models using the 500ss engine. This change could lead to engine failure. An area SKI-DOO dealership informed me that this would not be a problem if I was using the right plugs. When I bought the sled it had BR10ECS,which was new for that year. Later when I was stocking up on replacement plugs the dealer recomended going back to the BR9ECS plugs used in prior year 500ss motors because the colder BR10ECS plugs were fouling. Now the dealer is telling me to go back to the factory recomended BR10ECS plugs to prevent engine detonation. Any insight on this topic before the season would be great! THANKS

    • Member since
      July, 2005
    • From: pa
    Posted by dieselstroke on Wednesday, September 30, 2009 5:00 PM

    go up one size on the main jet.

    • Member since
      November, 2008
    Posted by jdmxz on Wednesday, September 30, 2009 7:00 PM

    Thanks for the help! A recomendation I picked up on the Doo-Talk forum reads like this; 400 main jets,20 pilots,1 1/2 turns out on the fuel screws,9dgm15-58 needles('07 MXZ) in the center clip position,stock shim plus a .020". Do I really need all of this to reduce the midrange hot spot and melting down a piston? Thanks!

    • Member since
      July, 2005
    • From: pa
    Posted by dieselstroke on Thursday, October 01, 2009 4:45 PM

    I don't think you need to do all that. they aren't that far off

    tag
    • Member since
      May, 2006
    Posted by tag on Sunday, October 04, 2009 8:13 PM

    I would still use the 9's in that engine

    • Member since
      August, 2005
    Posted by rzkid on Tuesday, October 13, 2009 7:40 PM
    What data do you personally have to back that statement up? After a full season of my own thrashing checking EGT, piston wash, and plug readings, I have found the 08 500ss jetting to be WAY off, to say the least. My findings are all posted on Doo-talk in the XP faq section. http://www.dootalk.com/forums/index.php?showtopic=279811&st=0 The stock 390 mains are just fine. Run it all day at WOT. Mid range is another story. Use needles from the 06 500 and raise them FULL RICH, with an addl .010 shim on the mag side, 15 pilots, 1 1/2 turns on the fuel screws, and running the 9s for plugs. The 06 needles have only 3 clip positions. Top slot is comparable to the middle slot on the 08 needle, so go full rich. This needle is also a bit richer than the 08. Ran this setup in temps from -15* to +30*. No fouled plugs, no burn-downs. I have ridden the sled in the woods like a grandma, held steady at the "hot rpm spot" for 4 miles, and the sled just kept on running. I've ran both low octane fuel and premium. Milage is usually 14-15 range, and I don't baby it. I ride. Some blame the cylinders, head design, timing....I believe it IS the jetting.
    • Member since
      November, 2008
    Posted by jdmxz on Thursday, October 15, 2009 10:48 PM

    Thanks for your help!  Do the carbs have to be removed to perform this change and how difficult is that? Also you mentioned that the '06 needles have 3 clip slots,would the bottom slot be full rich? I restore vintage race cars for a living so I have tools and mechanical skills I just lack two stroke/snowmobile knowledge. Thanks again!

    • Member since
      August, 2005
    Posted by rzkid on Friday, October 16, 2009 8:05 PM
    I leave the cables attached, and pull the carbs off the boots and tilt them to gain access. It is a tight space to work in, but after doing it so many times, I just deal with it. As for the needles, just remember that as you lower the clip, it raises the needle, and thus enrichens the circuit. IF you raise the clip, it drops the needle lower into the needle jet, and thus makes it leaner.
    • Member since
      November, 2008
    Posted by jdmxz on Tuesday, October 20, 2009 6:09 AM

    Thanks for the reply!

      If I perform the re-jetting,will the injection oil distribution need to be turned up a notch? Thanks for the input.

     

    • Member since
      November, 2007
    Posted by wiser 41 ski doo on Tuesday, October 20, 2009 6:29 PM
    br9eya is what i run
    • Member since
      August, 2005
    Posted by rzkid on Tuesday, October 20, 2009 9:24 PM
    I set my cable where it was 'supposed' to be, then fine tuned it to where I average a 40:1 ratio per tank of fuel.

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