2017 Sherco 250 Factory

Discussion in 'Trials' started by motobene, May 14, 2017.

  1. Norman Foley

    Norman Foley Devotee of the Husqvarna

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    No... I replaced mine with a long black rubber Motion Pro fuel/vent line. I routed it around the front of the carb and along left side frame and into the airbox. Keihin PWK carbs on my enduro bikes, have two long vent lines stock and I always route them into the airbox.
    #61
  2. Norman Foley

    Norman Foley Devotee of the Husqvarna

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    I thought it was from rubbing against the hot muffler. This slice was definitely not done to the Keihin on my '17 GG TXT125, as I had that carb out and looked at it. I did have it quit once when riding in snow, which I figured was from the bottom of the hose being close to the case and the snow melted, making a pool of water which blocked the vent. This would be prevented by the slice. It is protected, but that slice up gives me the willies!

    On enduro bikes we run the vent lines up, because of long water crossings. The vent lines are blocked by the water and fuel will stop flowing. You can tell who didn't do this... they are the guys who bikes quit half way across!
    #62
  3. motomaster132003

    motomaster132003 Adventurer

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    I played with the jetting a bit on my 17 Scorpa Factory 250 that is all stock other than the Spanish Fly Spark Arrestor.

    My testing is right at 2000 FT

    Stock jetting:

    125 Main
    42 Pilot
    Needle in the middle position.
    AS 3/4 turn out

    I tried 2nd clip from the top, but the bike would bog under quick full throttle openings.


    I ended up with:

    120 Main
    48 Pilot
    Stock Needle with clip in middle pos.

    AS 2 Turns out.

    If I set the AS under 1 3/4 to 2 turns out the engine wouldn't idle smoothly in 1st gear with the clutch out.

    At 2 turns out it will idle perfectly when doing full lock turns without a chug chug.

    I also noticed that I achieved the fastest idle at 2 turns out, so I had to turn down the idle to compensate
    #63
  4. motobene

    motobene Motoing for 46 years

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    The 48 jetting works if the way you ride is to idle around turns and not use deep throttle while heavily loaded. A 48 will produce soft-ish power and bogging under my hand.
    #64
  5. motobene

    motobene Motoing for 46 years

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    I rode again tonight and learned a bit more on the jetting. It can take me quite a few rides to hone in on the jetting in the fine points. I revised post #56 to reflect what I learned. Basically: With the 52 and the needle clip in the center position, I was getting a little dead spot in the low mid-range. A very small dead spot, so it took another ride to find it.

    I thought about the power on my `16 and remember it having a bit more. I a 55 low-speed jet in it. I will either move the clip down one or leave it as is and fit a 55, and test again.

    The '17 250 and a spark arrestor was a touch dirty off bottom with a 55, so the 52 went back in. My '16 with spark arrestor craved a 55.
    #65
  6. motomaster132003

    motomaster132003 Adventurer

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    Well we aren't all expert trials riders :D some of us are intermediate riders.
    #66
  7. motobene

    motobene Motoing for 46 years

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    I know of which you speak! I've had some pretty elaborate vent systems on previous off road bikes. I don't do Enduros anymore and hope to never again find myself in really deep water. Like...

    This Illinois trial in the `90s. Never been there before so I didn't know the terrain. Get there about start time. It had been raining a lot and they had this section IN a true river! I could not see the bottom and I didn't want to get the inside of my boot all squishy, so I didn't walk the section. The checker watched me plan to cut a big sweeping corner. He said nothing.
    Well right there, inside the tape, was this very deep pool. Bike and literally went down stream. I got out and spent some upside-down time pumping the motor out, thinking, "What an asshole thing to do!" I'm sure he and his buddies had a good laugh later. That made me hate really deep water as much as I hate slithery, sloppy mud!

    The deep water like that I just don't care to get into anymore, so these days I keep the carb vents simple and stock :-)
    #67
  8. 2whlrcr

    2whlrcr gooligan

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    Those Illinois people are assholes....:1drink
    #68
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  9. motobene

    motobene Motoing for 46 years

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    This is true, but there is more to this. Some riders will jet by making putt-putt-no-clutch the driving criterium, and changes are made is very small steps. When something improves with a small change the process stops.

    Jetting by putt putt can compromise other, more important criteria. And there are offsetting considerations like a more-open air screw or a needle clip position change. It is possible to have your putt-putt cake and eat the loaded-power cake too!

    I had a rider at a recent school on 300 GasGas. He's a careful, particular, detail-oriented fellow who rides the Intermediate line in local trials very well. Top in his class this year in the Texas State Series. During the tech session the afternoon before the school, I test ride bikes and ask permission to intervene in ergonomics, maintenance tricks, and carburetion. I tell my students my the goal should be for the bike to be the least in the way of learning for the school. When I change something, rarely do I find them changed back later (yes, I do look :-)

    At start of checking out a bike I ask, "Is it OK for me to touch your bike", and when given permission, I ride it and then work very fast and - depending on how suboptimal a bike is - can end up doing a flurry of changes. Despite his reservations, I put in a 55 in lieu of his 48. He's like... woah there! "Give it a try. We can easily swap back." Next day he repeated how it might not work for him.

    By the end of school day one he was 100% sold on the presumably fat jet. Over a beer that evening, he said how he thought that mod would crash and burn and how surprised he was that it didn't. He said there was no way he would have tried that jet on his own initiative.
    #69
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  10. motomaster132003

    motomaster132003 Adventurer

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    If you want to send a 52 or 55 pilot my way I would be happy to compare it to my 48 and report back :clap
    #70
  11. motobene

    motobene Motoing for 46 years

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    I have never read that Ohlins says their shock is not rebuildable. In fact, they are advertised as "fully rebuildable". At least on the SplatShop's website.[/QUOTE]

    FYI I stumbled onto this in my files today. It's a big red statement on the Ohlins valve sheet for their GG4512:



    FYI here is the top part of the sheet:



    I was corrected on why. GasGas saved a few bucks and didn't put a dodad called a fill station in the hat piece. Just a small threaded hole requiring a crude machine and messy filling process.

    It wouldn't surprise me if the shim stack and other specs were the same or nearly the same in the Ohlins for Sherco shock.
    #71
  12. Vintage pro

    Vintage pro Adventurer

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    Chris: sent you a shock diagram of the Sherco Ohlins to your E-Mail account, I have all of those cards on record in my files. Stacy Burger is the off road director at Ohlins and he couldn't find the shock card on Ohlins records.
    #72
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  13. motobene

    motobene Motoing for 46 years

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    Probably tight with Sherco, but looking inside we could document what's in there.
    #73
  14. motobene

    motobene Motoing for 46 years

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    Post #56 again revised regarding jetting.

    Bike is in the final setup for the first event next weekend. At least the many hours of left-side brake fabrication was done on the 2016 bike, so all I have to do is put it on.

    Quadboss ATV sealer did the trick on the mystery rear tire leak.
    #74
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  15. Bronco638

    Bronco638 Nobody Home

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    HEY! :dirtdog
    #75
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  16. motobene

    motobene Motoing for 46 years

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    Deep into the ass end now doing my left-side brake conversion. Nice that I made all the conversion parts last year for the former '16.

    Once again I'm finding the factory greasing rear-end bits all bashful and squeaky clean with that 'mere suggestion' of grease, or as in the case of the dog bones, no grease, just a sneeze if oil settling on the parts from the other side of the assembly plant. No wonder creaky Sherco isn't 'unheard of.'
    IMG_20170529_183525025.jpg IMG_20170529_181949011.jpg
    #76
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  17. motobene

    motobene Motoing for 46 years

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    Now this is what a fully packed right swingarm pivot looks like before assembly to the bike. IMG_20170529_185315478.jpg
    #77
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  18. motobene

    motobene Motoing for 46 years

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    8 hours of intensive setup.work today. Ready for the weekend event!

    IMG_20170530_173809032.jpg
    #78
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  19. motobene

    motobene Motoing for 46 years

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    Machined my own spark arrestor adapter from a chunk of easy to machine 7075. Here it is, mounted.

    IMG_20170530_173828184.jpg

    I had fit a 55 low-speed jet to fill in a slight dead spot just above idle, but as spark arrestor often do (from resonance changes and flow changes), the mixture got richer. The needle clip was in the middle position, so I though about dropping the needle by one clip notch. Then I realized the richness was sitting right on the bottom, requiring the air screw to open up to almost 3 turns.

    So I re fit the 52. Air screw is at two turns out, and power is as strong as it can be, everywhere.

    Friday I will be at altitude. I'll fit the smaller main jet, a 112, before I go. A test ride up there determine any further tweaks.
    #79
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  20. Bronco638

    Bronco638 Nobody Home

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    I don't recall the muffler end cap, on my '14 3.0 ST, having two screw holes (to mount the spark arrestor). Did you drill those or am I not paying attention (to my own bike)?
    #80