Broken Intake stud

Discussion in 'Motorized Bicycle General Discussion' started by ibcnya, Dec 4, 2008.

  1. ibcnya

    ibcnya New Member

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    Intake stud broke off in the engine and not backing out, loctite, WHAT NOW?
    Its below the surface and theres no way to get it by the tap out method. I dont have the tools to get it out either.

    What Now? This is my transportation. I promise you this though itll be put back together with Honda nuts and bolts. This really sux....have the whole motor off the bike for one broken stud...:(
     
  2. misteright1_99

    misteright1_99 New Member

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    Try a dremel with a coutoff wheel, and cut a slit into the engine casing til it cuts a slit into the broken stud. The heat up the engine casing (not the stud) and unscrew it with a flathead screwdriver.
     
  3. ibcnya

    ibcnya New Member

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    Ill have to source a dremel, what if I tried drilling it out. What are these kit studs made outta of anyways. Garbage...really, first the tensioner, now this, Im not that strong, I dont get it.: .bf.

    I wish I had a drill and a easy out...
     
  4. misteright1_99

    misteright1_99 New Member

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    You could try drilling it out, then retapping it to 1/4" .. These are the things you have to do with these engines. My advice would be replace ALL the studs while you have the engine out......

    P.S. My tensioner didnt last a day.........My spring tensioner has lasted over 1000 miles.....
     
  5. ibcnya

    ibcnya New Member

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    Im thinking make a dimple with a punch in the stud, then use a bit that fits that dimple, and drill out the center of the stud. This should allow the rest to turn out easier(maybe). I shoulda replaced all those studs, but kept putting it off. I broke it just doing standard bolt/nut check.
     
  6. Creative Engineering

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    ibcnya,

    I posted a solution regardng this very dilemna a few days ago...damn if I can can find it now...pictures included...maybe someone will help out with the link.

    Jim
     
  7. misteright1_99

    misteright1_99 New Member

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  8. bumleg

    bumleg New Member

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    you are right to centerpunch it.
    then buy yourself a left hand twist drill bit set (trust me you wont regret it)
    drill it out , usually the bit will back it out.
    if the bit wont catch an edge then you should use a stud extractor ....aka easyout. try to do it right the first time cause once you bugger it up it is hard to put back to rights.
     
  9. bumleg

    bumleg New Member

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    if it were me .. imho i would keep it M8 ,it gets anoying needing a fist full of wrenches to work on
     
  10. ibcnya

    ibcnya New Member

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    Read your post and have been trying that without heat for hours, with Loctite on those threads its not gonna back out. im gonna have to drill it with a small bit, follow up with a bigger, on so on until it decides to break loose. I dont wanna destroy the threads in the engine though.

    Anyone ever just use bolts instead of the stud/nut combo? I think as long as I use loctite they shouldnt back out at all.
     
  11. xPosTech

    xPosTech The Old Master Motorized Bicycle Builder

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    If you continue with right hand drill bits, you will get to the threads in the cylinder boss before it breaks loose. As the bit heats up the bolt, the bit direction will keep tightening it.

    With left hand bits, the heat of the drilling will liquefy the Loctite and the bit direction will most of the time back out the bolt without resorting to the E-Z Out.

    The tap, tap takes patience and light taps to keep from deforming the bolt and locking it tighter as it deforms.

    Bolt length is too critical to use for manifolds. A hair too long and they bottom out, too short and they don't grip enough thread depth. Add gasket crush thickness and you just don't know.

    Have you ever had to torque down a long bolt through two pieces of metal while holding a backup on the wrench? Know how much harder it is turning that bolt than just torquing down the nut? You can't get a reliable torque reading turning a bolt rather than just the nut. The studs have their own torque rating.

    Ace Hardware usually has automotive quality metric studs for the intake and exhaust but none long enough for the mounts. Expensive. :eek:

    Ted
     
    #11 xPosTech, Dec 4, 2008
    Last edited: Dec 4, 2008
  12. Creative Engineering

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    Yeah you're right about the locktite. It does add a whole new dimension, especially if it's the red.

    If you do drill it out to about a .030 wall, you can collapse what's left with a center punch so that you don't destroy the threads in the cylinder.

    Left hand drill bits work like a charm...just as Ted & bumleg stated. They can be hard to find especially when you want one now!!

    Jim
     
    #12 Creative Engineering, Dec 5, 2008
    Last edited: Dec 5, 2008
  13. Creative Engineering

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    This reminds me:

    Paul, Ghosto,

    Are you guys stll working on a hardware kit?

    Jim
     
  14. Ghost0

    Ghost0 New Member

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    We are and was actually supposed to pick them up today but our supplier is short one of the studs so it looks like we won't have them available until next week. Will be cool though, complete hardware replacement kit, will replace every nut, bolt, stud and washer on the engine except the cylinder studs and the case bolts at the base of the cylinder. All ZP grade 5 or better hardware.
     
  15. eDJ

    eDJ New Member

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    There is a Harbor Freight tool store at KANNAPOLIS, NC. I don't know just how far that is from you but they have inexpensive knock-off's of Dremel tools, and a variety of stud extractors. Big sale in progress there this month too.

    Bikeguy Joe has a post on making these China Girl motors more bullet proof. Refitting these motors with some grade 5 or 8 cut off bolts where a Dremel wheel could cut off the head and dress the threads to make good durable studs for intake and exhaust & mounting might be worthwhile. I'd imagine even head bolts too if you can find bolts long enough for the conversion. (Tractor Supply ?)

    Bicycle Motor Preperation And Care

    http://motorbicycling.com/f30/bicycle-motor-preperation-care-354.html

    Some may see the merit of a flat washer placed on the stud first, then a lock washer with the nut tightened down to 15 flbs.

    Speaking of Tractor Supply, Mr Right1_99 has a thread on a better spring loaded chain tensoner here:

    Motorized Bicycle Spring Loaded Chain Tensioner

    http://motorbicycling.com/f30/motorized-bicycle-spring-loaded-chain-tensioner-1128.html

    So, if ya got the motor off the bike, now's a good time to consider upgrading the studs & fastenings with grade 5's or 8's. The head bolts could be done later with the motor in the frame probably. (just whatever you want to do...perhaps wait till warmer weather for that)
     
  16. ibcnya

    ibcnya New Member

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    Way ahead of you on that, I have the engine apart and a bag of bolts to take to the Northern tool we have here. They will all be replaced with Hex head bolts and the mount studs are being replaced with threaded rod. Im even upgrading the float bowl bolts and hardware.

    I replaced my tensioner with one of Dax's bearing upgraded versions weeks ago....

    BTW...I live in Concord, which is Kannapolis's neighbor on the map.
     
  17. eDJ

    eDJ New Member

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    LOL , yeah I googled Concord's zip and then went in Harbor Freight's web site
    to see if there were any close to you. It listed Kannapolis's location around
    6.7 miles away. But there were three zip's for Concord, NC so I just guessed.

    Harbor is about as good as it gets where I live. :D
     
  18. bumleg

    bumleg New Member

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    bolts will work.
    studs are prefered in alluminum though due to the possibility of stripping when loosening or tightening
     
  19. ibcnya

    ibcnya New Member

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    Studs are always gonna own bolts. Like when you stud a head on a engine. Bolts only push a object to something, the oject can only go so far before the bolt begins to pull threads. A stud clamps/pulls from both directions, forcing the parts together differently. I always use ARP headstuds on my engine builds when possible. Most ppl are to cheap to payout for a set but I find the worth it, on a car put together for racing where the head will be removed frequently.

    Ive decided to source my intake/exhaust studs from honda intake manifolds. They use 3-4 studs dependind on the model, and they are the same thread and metric at that. Im sure i know a model that has some that will work. I had no luck finding any studs at Advance auto or Northern Tool. This engine's fasteners will be bullet-proof when im done.

    Planning to look in to this for ideas.

    http://www.arp-bolts.com/news/Images.News/BoltBinFlyer4.pdf
     
  20. ibcnya

    ibcnya New Member

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