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  1. #1
    Mark22's Avatar
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    787 Startup After Rebuild

    I've finally got my 97 XP fired up and running. I ordered a pint bottle of Dumonde Break-In oil and I'm in the process of breaking the 787 in. I trying to follow the directions to the letter so I get the best running engine possible. It said to richen the carbs for break-in. Does this mean adjust the low speed screws? I've got the idle turned down as far as I can get it to go and stay running. I've also adjusted the low speed screws counter clockwise about 1/2 a turn. I've got a K&N air cleaner on it too, if that make a difference. I've only done 4 1 minute heat cycles so far and this thing smokes like crazy when it runs. Is that normal for the Dumonde oil? It also sounds like its knocking. Is that normal for a break-in or do have the idle too low?

    Thanks

    Mark


  2. #2
    mibunkerking's Avatar
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    the low idle will cause it to knock to a point. it should go away with rpms but stay on the procedure till you get to that point.

    as long as you rejetted our carbs for the K&N you should be fine.

    it will smoke alot at first. its burning off all the lube from assembly. plus your running your carbs rich so dont worry about it.

  3. #3
    Zeke says hi! BLK MAJK's Avatar
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    yep, it will smoke....here is mine doing one of the heat cycles in the water...mine is the white one.....note that both skis are running....


  4. #4
    Mark22's Avatar
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    Quote Originally Posted by mibunkerking View Post
    the low idle will cause it to knock to a point. it should go away with rpms but stay on the procedure till you get to that point.

    as long as you rejetted our carbs for the K&N you should be fine.

    it will smoke alot at first. its burning off all the lube from assembly. plus your running your carbs rich so dont worry about it.
    I kinda thought that a low idle was causing the knock, but I wasn't really sure. I've got a mechanic's stethoscope and I've been listening for grinding or mechanical knocking. I didn't hear anything out of the ordinary. I didn't rejet the carbs... I've been looking all over for some specific info on jetting for my K&N. I'm not revving much above idle, so I figured that I would be OK through the initial startup. Can you get away with adjusting the high speed screw instead of rejetting?

  5. #5

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    not rejetting and only 1/2 out on the lows is not running the carbs rich.........

    normal lows are 1-1.5 out highs closed to 1/4 out OEM specs.

    TLR

  6. #6
    Mark22's Avatar
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    Quote Originally Posted by TLR View Post
    not rejetting and only 1/2 out on the lows is not running the carbs rich.........

    normal lows are 1-1.5 out highs closed to 1/4 out OEM specs.

    TLR
    I adjusted the lows 1/2 turn out beyond the stock setting. So I guess it would be closer to 2 turns out.

  7. #7
    mibunkerking's Avatar
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    you are still to lean because the K&N is flowing more air than the stock airbox. i would stop running it till you correct the jet sizes. then start your break in over again.

  8. #8
    Mark22's Avatar
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    Do I need to change the high speed jet and the low speed jet both?

  9. #9
    Mark22's Avatar
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    I've been doing a like research and it looks like everyone who has a R&D changes to a 2.0 n/s 80g spring and 75 pilot jet. Do I not need to change the main jets?

  10. #10
    mibunkerking's Avatar
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    you need to change both the low and high speed jets to correct for the increased airflow through the carbs. hopefully someone on here will chime in with the correct size jets as i can remmeber.

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