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Thread: 916, etc throttle bodies on 851?

  1. #31
    Join Date
    Jun 2007
    Location
    Melbourne, Australia
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    1,310

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    i'm way too lazy to replace the closing springs on an engine in the chassis. i don't need that sort of agro. and too lazy to pull the heads. so it'll stay as it is i expect.
    Brad The Bike Boy

    www.bikeboy.org

  2. #32
    Join Date
    Jan 2010
    Location
    france
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    I understand you haven't only one to look after! In my case , only one.
    i spent so many hours of settings, disassemblies, mappings, trials etc...that when i discovered it was the main cause of this crappy running at low revs, i throw myself on the heads and these poor springs.
    I operated on the bike, it's not easy but faisable.
    So you have to drive it like a Superbike, in fact its first target, from 5000 rev😊
    Mine now is so nervous and happy to hight rev with the heavy springs and overall the cam timing, that I decreased the red zones (fuel and ignition cuts) at 9500 revs to secure the crankshaft.

  3. #33
    Join Date
    Jun 2007
    Location
    Melbourne, Australia
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    1,310

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    i'm sure we spoke about this years ago. i was a little concerned as to the reliability of the 1.5mm collets and the heavier springs. but really, laziness is the bigger issue.

    i did make a tool a while ago for flipping the spring tails in with heads on engines. funny, some days it works with no effort, some days it's still a nightmare

    i rode it the other day with all its low speed crankiness. i'm sure it's going to shit me endlessly until i do actually fix it.
    Brad The Bike Boy

    www.bikeboy.org

  4. #34
    Join Date
    Jan 2010
    Location
    france
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    41

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    Yes Brad we spent a lot of discussions on this 90 bike!
    I was confident with the stronger valve springs and small rings couple, because my friend 91 one had it (i saw the springs on it for sure, and the valves are the sames in 91)
    For information, after a few thousand of kms including a few harder uses, on track demonstrations (the reason why i set the cuts at 9500 &#128567, i recently checked and set the valves plays, the 1.5 rings haven't (yet...?) shown worrisome traces of crushing or wears.
    Hoping again a long life to it ,and yours; now 67000 kms, no signs of weakness.
    Pat

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