Helical Gear Stuck

Discussion in '2 Stroke Bicycle Engines & Kits' started by ninjaplatypus42, Dec 29, 2016.

  1. ninjaplatypus42

    ninjaplatypus42 New Member

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    I'm trying to install a centrifugal clutch but the threads on the inside of the small helical gear on the engine are stripped. How else can i get the gear off besides the puller tool? I've already tried riding with the sparkplug out to try to wiggle it off to no avail.
     
  2. crassius

    crassius Active Member

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    take out clutch, ascertain where key slot is in gear, cut down into gear to meet slot
     
  3. ninjaplatypus42

    ninjaplatypus42 New Member

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    Taking out the clutch would require taking most of the engine apart yes? That's definitely an option but it's my last resort. I may try to cut the gear off without taking anything apart.
     
  4. crassius

    crassius Active Member

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    there is more room to get a puller onto the drive sprocket on other side, then whole clutch and shaft can be driven right out giving way more room for tools on clutch side (note: take out bucking bar and put short bolt into hole in shaft to protect in when using a regular puller)
     
  5. sbest

    sbest New Member

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    Remove the bolt and washer retaining the helical gear.
    Set a much longer bolt to the depth of the threads.
    Heat the helical gear with a propane torch, but not the crankshaft.
    With 2 flat screwdrivers putt a little load on the helical gear.
    Give the long bolt a sharp snap with a steel hammer.
    Helical gear should come loose.
    Do NOT beat on the end of the crankshaft or beat the bolt unmercifully.

    Examples from webland:
    [​IMG]

    [​IMG]

    [​IMG]
     
    #5 sbest, Dec 29, 2016
    Last edited: Dec 30, 2016
  6. Kioshk

    Kioshk Active Member

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  7. ninjaplatypus42

    ninjaplatypus42 New Member

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    I've tried all the above methods and also JB welded the tool to the gear which still didnt work. Any other ideas? I've got pretty much the whole engine apart at this point so that's not an issue. I also tried just cutting the damn thing off but all i have with a metal cutting blade is a reciprocating saw and there's just not enough room.
     
  8. sbest

    sbest New Member

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    Cut the recip blade to the minimum length needed and come down from the end into the key as Crassius suggests. You don't need to cut right through or into the key or even right to the back of the gear, just make a big cut into it. Do it at 180 degrees as well if want too. Now, set the gear on a steel brace like a block or anvil and whack it with a cold chisel and big hammer (BFH - Big Friggen Hammer). This will spread the gear's bore enough to slide it off.

    I've done it with much larger gears.

    Steve
     
  9. ninjaplatypus42

    ninjaplatypus42 New Member

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    I see what you and Crassius mean now, it worked! Thanks guys.
     

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