2017 Sherco 250 Factory

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

  1. motobene

    motobene Motoing for 46 years

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    4,090
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    The left-side brake conversion went very smoothly. No dreaded bleeding problems.

    I stored the master cylinder and reservoir full, by machining an adapter, same inside diameter as a banjo fitting, that was a plug. When I had the swing arm off, I made sure the rear brake line and caliper were also full, and I fit an M10 X 1.0 cap I machined.

    Upon assembly the two caps were both at the high point. I opened the reservoir to let it gravity feed through the reservoir, and quickly removed the caps and fit the brake line. There was flow out the fitting when I tightened the banjo for zero air in the system.

    The rear brake pedal was firm immediately with no on-bike forced bleeding. A first!

    IMG_20170531_085017665.jpg
    #81
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  2. motobene

    motobene Motoing for 46 years

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    Last year I cobbled together a slip-in adapter. This year both are screw on, so yes, one must drill undersize holes through the thin end cap.
    #82
  3. motobene

    motobene Motoing for 46 years

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    A word about this particular bike. I'm very happy with it! It's a sweet one. I worry when I sell a bike as sweet as my '16, as it's replacement might not have as good a personality.

    This one has below-average vibration and motor noises.

    Finding neutral at my preferred clutch lever position is sticky when stopped, so I do that rolling to a stop. The 125 fully releases the clutch. Maybe that is because of the reduced diaphragm-spring preload? Clutch lever pull is about 40% more than my '16s 4-springs clutch, but the action is about 60% better.

    Final drive is geared down for '17, about the equivalent to a 45 point something rear sprocket on a '16 (I had a 44). I'm really liking the change.

    The handling went from excellent on the '16 to superb on the '17. A mystery uptick in individualism. I am in love with the late-model Sherco-Scorpa feel. I've heard many riders comment on the 'plantedness' of these bikes - the stability and precision. This particular bike has the front and rear sag spot on in the steering department. I think and it does, and I can stop balanced on a variety of terrain for long, stationary pauses.

    It's like a fine wine.

    If only my old back would stop giving me fits, I could make fuller use of this thing! I walk half the time bent forward like an old codger, and the problem is not healing like it should since May of '16 :-0

    That is my fine whine!
    #83
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  4. Vintage pro

    Vintage pro Adventurer

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    Chris: This is Randy, look at your E-Mail I have the shock card code for the Ohlins. Looks slightly stiffer than mine, the shaft jet will also need to be opened up with a valving change. Here is my original set-up that's now somewhat lighter.

    Attached Files:

    #84
  5. motobene

    motobene Motoing for 46 years

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    Randy, thanks a ton for passing the shock build card onto me! Now I can compare with other Ohlins I've been into.

    Looking forward to trying the modified Sherco Ohlins (without remote reservoir). I know you will improve the stock Sherco Ohlins. I like your ideas on improving negative and positive travel.

    In the photos, I see you like your rebound and compression 'rocker shims' in the third positions from the piston. I sometimes like two rocker shims in the rebound stack, say, in positions two and four. I need to learn more about changing shaft orifice diameters.
    #85
  6. motobene

    motobene Motoing for 46 years

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    Fun first Si-Pa-Pu ride. I double crashed my way into 4th Expert in a tight field. Excellent sections and no deluge as originally forecast.

    This morning I'm slowly getting going. Task one was to not injure myself taking a shower. Unfortunately, I move very old Manish in the mornings. Now I'm wondering if I'll have the stamina to hold up under 24 Trevor Clancy TM sections. What the heck. It's all for fun.

    On the tech side a reminder of the significant variable of bike (including carburetor) individuality.

    While the 2017 Sherco 125 runs gloriously perfect at 7k plus altitude with 115 main and 58 low-speed jets, and needle clip in mid slot, the 2017 250 is not following my 2016 specs and the general pattern. It cannot handle a 55 low-speed jet. Even the 52 was a touch blubbery on bottom. In both cases the mid was leanish with bogging with fast throttle openings, needle clip in the middle slot.

    In '16 I fit Boyesen CarbonTech reeds to deal positively with some contradictions in jetting. In 2017 I fit them before riding the bike, so I'm missing what jets the bike would 'asking for' with the stock reeds. My bad.

    What's working for me at 7k plus is 112 and 50, with air screw 2-1/2 out. This bike might be 'asking for' a 48, though once loaded the motor is very tractor like. The needle clip got moved down one slot to 2nd from bottom to enrich the mid, and that fixed the bog. I haven't fit an under-50 low-speed jet to any Keihin bike in long time, and I didn't bring one. That experiment will have to wait until I return home.

    Following 'recipes' in jetting like this model needs these exact jets just does not work to capture all bikes.
    #86
  7. motobene

    motobene Motoing for 46 years

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    Another tidbit. The suspension broke in during the event yesterday, speeding up. I had to dial in some fork and shock clicks because the bike was getting too reactive in sections with lots of rocks.
    #87
  8. motobene

    motobene Motoing for 46 years

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    Day two Expert class at Sipapu I had a great ride going, then crashed, then stalled in a section and then stalled again in another section! The stalls weren't from low idle setting, but in part from a changing idle setting.

    This particular Keihin carburetor is giving me some jetting fits. I'm getting inconsistent fuel delivery off bottom, with the idle rising then lowering. Very clean running, then it'll enrich just enough to lower the idle and cause some problems.

    The period of the idle change is long, as in several minutes, and the rpm change isn't much. Hmm. This Keihin ain't so perfect, and now I'm thinking that's why it can't handle my usual +10 or +13 low-speed jet.

    The bike will run perfect with a 50, then next section the idle will drop. Add a little normal jostle enrichment and brief moment of lack of attention can cause a stall.

    I can buy a new float needle and seat and hope the problem isn't in the 'tower', but will first fit a 48 when swapping the high-altitude main jet for the low. A 48 will be the smallest low-speed jet I've used in a 250/300 for many years. Hoping that works so I can leave the needle and seat alone.
    #88
  9. mmanniko

    mmanniko Adventurer

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    Curious what you find Evan's 16 125 had similar symptoms, would get really lean but never consistent enough to diagnose. You might have noticed in KS when we were in the same group. We made it work by being too rich until we changed bikes. Not sure how they fixed it.
    #89
  10. Yard Sale

    Yard Sale Long timer

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    I had the same problem after the update. After plugging in your phone, swipe down from the top. It will present a menu. Choose the second option to let it transfer files.
    #90
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  11. motobene

    motobene Motoing for 46 years

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    A problem - or benefit - with Android is there is no one Android, so a simple go here and do that more often leads to a dead end. Every company has it's own Android flavor.

    I have to go deeper into the Droid Turbo menus to find MTP (media transfer protocol) settings. MTP is enabled yet I still can't see my files over USB. Nice that the forum software now allows photos to be uploaded directly from my phone.
    #91
  12. motobene

    motobene Motoing for 46 years

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    I think this problem happens more often than we think, and ranges from merely irritating to debilitating.

    One test is to put the 125 carb on the 250, rejetted of course. This would test the carb itself. No variability would mean I probably have a carb body or float needle/seat problem.
    #92
  13. Beatprojim

    Beatprojim Beatprojim

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    I just finished going over my slightly used 17 Sherco Factory 300 and setting it us as close as possible to my 50 hour 16 Sherco Factory 300. The 16 will be my main bike for a while - the 17 was an accidental pickup. Riding them back to back for the first time was very interesting. First, the 17 gearing is noticibly lower. I had to do the clutch "burn in" as, like bene, the bike would not shift to neutral while standing still. After the burn-in, it went to neutral. I am running a 48 pilot on the 16 but since that was my only 48, I popped a 50 in, set air screw 2 turns out. It ran noticeably spunkier than the 16. Jettting or just being 50 hours fresher?? I'm recovering from an injury so pretty light riding but that is what I have noticed so far
    #93
  14. Beatprojim

    Beatprojim Beatprojim

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    Forgot to mention how rattely the clutch is sounding on the 17 at this point. Sorry, but a few beers into the evening I'm trying to remember exactly but I believe at low Rpms, clutch out, and quite a rattle. Pull clutch in and it goes away. I will take cover off to see if anything is loose but much noisier than 16, So far
    #94
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  15. Norman Foley

    Norman Foley Devotee of the Husqvarna

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    My '17 Scorpa clutch is noisy, with the lever out. Noisier than my '17 Gas Gas with similar clutch. Nature of the beast...
    #95
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  16. motobene

    motobene Motoing for 46 years

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    Given the lower inertia if the 125 flywheel, the compression impulses 'light up" the primary gear running clearance on the 125 significantly more than on my 250 or a 300. Some added flywheel weight would quietens things on the 125.

    As for jetting, my '17 250 refuses to follow in the footsteps of my '16 with it's love of 55 low-speed jet. I tried 52, then 50, and now 48.

    This particular bike runs cleaner but less strongly on the 48, but I have no choice. I need a T shirt with this phrase:

    "I used to be dogmatic, then I jetted more motorcycles."

    For now, at 1,600 feet:
    120
    48
    2nd from bottom needle clip
    1-3/4 out air screw
    #96
  17. motobene

    motobene Motoing for 46 years

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    More rides testing the R Racing-Modified non-external-reservoir Ohlins, which I love.

    The jetting would be considered spot on by many, but I'm not there yet, so more carb mods and others to come....
    #97
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  18. motobene

    motobene Motoing for 46 years

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    Update on jetting:

    My 2017 Sherco 250 with Keihin has broken a long-running pattern. My '16 loved a 55 low-speed jet, but not my '17. I've come down in steps from 55 to 45 (stock is 42), to get it to clean up right off bottom. Now I'm at 120 (stock is 125)/45 with air screw 1-1/2 turns out.

    That did the trick to clean things up (though some loaded-power loss resulted). To make this smaller low-speed jet work, I had to raise the needle to maximum, clip in lowest slot. In the next slot up I get some bogging. Anything leaner, like clip in middle position or higher is just, well, pathetic.

    This bike has been a confirmation of bike individuality, and the need sometimes to iterate problem bikes for many months because they refuse to follow 'cooking (jetting) by recipe.'

    This bike was 'asking for' less fuel in a narrow spot from idle to the mid transition and I was hard of hearing because it was outside what I expected should be the case.

    Contrast the '17 250 with my '17 125. The little guy runs awesomely with a 58 low-speed jet (stock is 50), the same 120 main jet (stock is 125), and the needle clip in the middle slot.
    #98
  19. motobene

    motobene Motoing for 46 years

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    Rode many hours in 100% humidity and hot. Had to open the air screw to compensate, but otherwise the bike runs quite strongly and cleanly.

    The R Racing-modified internal reservoir Ohlins is proving to be a dream shock. Vintage pro is sending me a 50 N/mm spring to see if going even softer (stock is 65, and currently is has a 60 with only 1mm preload) will increase performance even more.

    I can run more preload with the 50 and not mess up the steering. The key question being, will it feel like it's bottoming hard? Modified and with the 60, it feels 'bottomless.'
    #99
  20. motobene

    motobene Motoing for 46 years

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    Updates to jetting, clutch, and modified Ohlins shock:

    Jetting my '17 to my high standards has been tough. The bike just won't tolerate low-speed jets over 50 the '16 loved a 55). I've had to work my way into some settings and am happy to report I'm 90% of the way to meeting my high standards.

    The latest is smaller low-speed jet, needle all the way up, and lowered float bowl fuel level, dropping the float 3 mm more. That cleaned up some richness as the slide cracks open or when jostling on angled terrain, while not seeming to change jetting noticeably.

    I've also thoroughly tested a modified Ohlins shock with more travel (very nice!), with 60N/mm spring (better) and stock 65 N/mm spring (acceptable). The modified Ohlins is very noticeably superior to the stock Ohlins!

    I also fit a spring retainer plate from a 125 for easier clutch pull and still excellent IMG_20170822_105233140.jpg IMG_20170822_110302733.jpg IMG_20170822_111246108.jpg IMG_20170816_173053354.jpg engagement feel and speed.