My 950 Refresh or Mission Creep...

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by sakurama, May 5, 2009.

  1. LocuL

    LocuL Gnarly Infantry

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    Thoughts about the 1x1 drive:
    If you choose to go for the Safaris i can help you with data regarding which material for vvelding.
  2. Deadly99

    Deadly99 Fast and Far

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    Oh la la :thumb

    I'd change the seat cover so the stripe down the center is orange....

    Looking very sweet :clap


  3. Keith

    Keith Slabbing it

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    I was just across the freeway doing a little Go Karting at SyKart the other day.
    Small world...

    Good luck with the sale and looking forward to more creep.
  4. tinwelp

    tinwelp Professional Idiot

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    All,
    thought I owed a bit of an update on my progress with the external choke set-up. The news is mixed. All is installed and functioning reasonably well with adjustable fuel and air jets. Here's a general view of the installation:

    [​IMG]

    The horizontal aluminium cylinders with the square bases are the mixing chambers and control valves, showing cables exiting at the left hand side... you can just see a brass adjuster for one of the cables... which are controlled by the OEM lever and some custom-built cables. The two throttle valves in the foreground are the air inlets which are plumbed into one of Chris' velocity stacks (which are FANTASTIC pieces of kit by the way Chris... many thanks!!):

    [​IMG]

    At the base of each aluminium cylinder is the fuel inlet (small-bore tube), each fed from the float-bowl of the respective carb., again with a throttle valve in each feed:

    [​IMG]

    On the far side of each of the aluminium cylinders are the mixture outlets, each feeding to the existing inlet vacuum-port tapping (normally blanked with an M6 screw), the fitting containing an emulsifyer jet (actually an FCR idle jet!!) which pokes into the inlet tract:

    [​IMG]

    I'm still far from content with the solution as each time I start the bike I need to fiddle with the jet settings for it to fast-idle well on choke. I suspect that the outlet from the mixing chamber is just too far away from the inlet port; sometimes I get a well prepared mixture, more often it all condenses back to liquid interspersed with air bubbles.

    My next step is to mount the mixing chambers directly to the inlet port tappings to try to avoid this, then maybe play around with the size of the injection jets a little.

    I'm convinced this solution will work well once I manage to dial it in correctly. The only question is if I'll finish before the decent riding weather arrives... at which point all bets are off as I'd rather ride, despite this turning into an interesting little project.

    I'm still watching and waiting to see how the internal choke works out too. No doubt it'll be a much more elegant solution than mine.

    Cheers... Paul
  5. brents347

    brents347 Trusting my Cape...

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    Paul,

    Your solution has lots of external 'stuff', but it looks well thought out and assembled. Nice work.
  6. sakurama

    sakurama on an endless build

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    That's impressive stuff Paul.

    As an update on my front I'm in NYC as of this morning and I intend to test our carbs once my shoot is done on Thursday. Chris? You ready?

    I sold my Husaberg....

    [​IMG]

    much faster than I anticipated. I'll admit it looks better in his pickup than mine. It's going to become a ski bike oddly enough. At least that means I should be getting parts from Christini in the next week or so.

    The end of this week is going to be spent boxing up my shop to move in two weeks. I head back to Portland next week to demo the garage and then back to NYC to pack up the shop and drive it cross country. Really wish I had more time to prep the garage but it's not to be.

    By the spring things should be a bit more settled and my 990 should be on the west coast. With no dirt bike it will be my only off road machine so I intend to single track her this summer. No mercy.

    Gregor
  7. MortimerSickle

    MortimerSickle Semi-Adventurer

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    :yikes
  8. tinwelp

    tinwelp Professional Idiot

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    Brents,
    yep... I agree. Not exactly elegant, but I'll take function over form if it gets me started quicker from cold with no risk of a flat battery!

    If and when I ever get settled on a single adjustment position for the throttle valves, I'll replace them with fixed jets. That'll remove a bit of the clutter. It just needs a bit of time and patience...


    Gregor,
    sad to see the Husaberg leaving like that. I've also got a bit of a soft-spot for "the Swedish exotica". Mine is way older and scruffier (FE400), but I've had it a long time and it still puts a smile on my face tearing around the local trails.

    Good luck with the move.

    Cheers to all... Paul
  9. charlie264

    charlie264 Long timer

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    Seems to me an easier, simpler, cheaper solution. Older bikes with non choke carbs used a primer pump, a small jet on the inlet manifold squirted fuel directly in the carbs.

    [​IMG]
  10. sakurama

    sakurama on an endless build

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    Well sort of.

    There's difference to priming the bike with fuel and correctly metering the fuel through a choke circuit that will allow the bike to sit and idle easily so that it can warm up. The accelerator pumps can squirt raw fuel into the intake too but they can't meter a suitably rich and well mixed gas air blend continuously so that the bike can idle reliably. A choke is the right way to do it and thus our effort is to make a true choke. I'm guess this is why you don't see squeeze bulbs on many bikes. :eek1

    Gregor
  11. charlie264

    charlie264 Long timer

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    Yeh, but it gives you a fine mist, unlike carb priming, once started you'll need to control idle with the right wrist....:wink: See no reason why it wouldn't work.
  12. tinwelp

    tinwelp Professional Idiot

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  13. sakurama

    sakurama on an endless build

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    I think anyone who has FCR's can attest that the throttle can't keep the bike idling. Many of us have drained our batteries between the constant AP priming, stalling, priming and restarting. It's enough of a hassle that people have taken the carbs off.

    Paul, those are mid body gaskets for the FCR-MX - a different carb that already has a choke.

    Gregor
  14. snowhawk jockey

    snowhawk jockey Slack Jaw Gaper

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    The mold for Keihn mid-body orings are a CNC program away, for a tooled up tech like Chris. I imagine if there are any real glitches that involve the gasket, he'll just zip out a mold cavity and cap, to squeese down some silicone.
  15. Orangecicle

    Orangecicle On a "Quest"

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    Stupid question on the choke issue. In this context, would it be possible to create an external choke on this kind of carb by putting either a horizontal slider on top of the trumpets or a butterfly on top of the trumpets? Just curious.
  16. dieselcruiserhead

    dieselcruiserhead Long timer

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    maybe I missed it but are there any comparisons to the OEM 950 carbs anywhere?
  17. DRjoe

    DRjoe Long timer

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    Nice solution tinwelp

    I was thinking of doing something similar but using an electric primer from an outboard engine
  18. snowhawk jockey

    snowhawk jockey Slack Jaw Gaper

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    Plenty of dyno runs on stock carbs in the OC. Figger 89hp+/- with stock carbs and cans.

    The key to the FCR is its responsive behavior, due in large part to the acc pumps and direct connection of throttle cable to the slide, not its dyno results. For example, with the FCRs, there is no delay between twisting the grip and the bike wheeling. The delay is clearly evident with the stock CVM vaccum slides.

    It is effortless to keep the front light while bumping through baby heads or sand pits, with the FCRs, just by blipping the throttle whenever you want to lighten it up. The same baby heads or sand pits with stock carbs, are a calculation of when to hit the gas and how long the carbs take to respond or having to plow through on a smooth and steady throttle.
  19. CosentinoEngineering

    CosentinoEngineering Been here awhile

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    >>thought I owed a bit of an update on my progress with the external choke set-up. The
    >>news is mixed. All is installed and functioning reasonably well with adjustable fuel and air
    >>jets. Here's a general view of the installation:

    Wow, a lot going on there! Looks like an industrial pneumatic installation. My choke is nearing completion (yes, its been that way for a while) and we'll be running it with Gregor this Thursday. Its a nice tidy solution but tearing the carbs apart and getting them back together is a pain in the ass.

    >>maybe I missed it but are there any comparisons to the OEM 950 carbs anywhere?

    The OEM 950 carbs are CV style that have a choke circuit as standard. The CV is a compeltely different style carb and not too performance oriented.

    >>Stupid question on the choke issue. In this context, would it be possible to create an external choke
    >>on this kind of carb by putting either a horizontal slider on top of the trumpets or a butterfly on top
    >>of the trumpets? Just curious.

    For a choke you need a new air and fuel circuit and some way to mix the two and some way to isolate it from the other fueling circuits at larger throttle openings. However this is accomplished is irrevelant, I am doing it in-carb because all the features are already there but just not machined.


    Also as a side note, if anybody has the chance to buy an ex-sakurama bike go for it. They are so nicely accessorized.
  20. sakurama

    sakurama on an endless build

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    Well, yesterday I was supposed to be packing up my shop for the move across country. Instead I finished my work at the studio and Chris was headed to the anodizer so he picked me up. Was interested to see the anodizing process but all we really got was a quick peak. Sort of medieval looking.

    [​IMG]

    Chris got the new TPS brackets and the choke parts anodized orange as well.

    [​IMG]

    Then milled a 12mm wrench flat on the part to assist in screwing it in.

    [​IMG]

    And installed them. Sort of.

    [​IMG]

    Yesterday was one of those days where it seems things don't go right. I decided to edit some video (a first) and, well, it sort of tells the story. Sometimes the magic works and sometimes it doesn't...

    <iframe frameborder="0" scrolling="no" width="640" height="360" src="http://api.smugmug.com/services/embed/2346039548_DQqKBxz?width=640&height=360&albumId=22082238&albumKey=DFRZkq"></iframe>

    Gregor