Huffy Horror Story (kinda)

Discussion in 'Motorized Bicycle General Discussion' started by CranbrookKid, Sep 18, 2013.

  1. CranbrookKid

    CranbrookKid New Member

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    I've had this huffy cranbrook for about half a year and it has caused me a few headaches. First 50 mi. it rode silky smooth with a good amount of power, hit 36 mph. Then the intake studs basically fell out. Replaced those with standard thread and rode for a bit until today when the right intake stud needed replacing again. Fixed it (sorta, I couldn't fully tighten it or it would unscrew out), and went for a ride. Barely had any power and the sucker smoked like a magic show. Came home, unscrewed the head nuts, and out came the studs for the head. What to do now? I'm thinking of replacing all of the hardware(+studs) and getting a new top end. Would it be smarter in the long run to just shell out the money for a new motor?
     

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  2. maniac57

    maniac57 Old, Fat, and still faster than you

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    A replacement motor would be the easier route.
    You can get them about $90-100 bucks for just the engine.
    Dax also has a sweet balanced bottom end you might consider...it will cost a bit more to get the correct needed top end parts but you'll end up with a very nice engine from all the reports.
    Figure somewhere around $150 or so for the Dax and top end.
     
    #2 maniac57, Sep 18, 2013
    Last edited: Sep 18, 2013
  3. 2door

    2door Moderator
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    Those chrome acorn nuts are why the studs came out of the case. I'll guarantee you that if you try to remove them from the suds you'll find them bottomed out on the threads and the threads damaged.

    Put the studs in a vice and get those acorn nuts off. Throw them in the trash and go buy a die, either 8mm x 1 or 1.25 thread and rethread the studs. Double nut them and torque them back in the case, 120 to 140 inch pounds, install a new head gasket and instead of the acorn nuts secure the cylinder head with shouldered/flanged hex nuts and you'll be on your way. Remove and discard the studs in your intake and exhaust manifolds and replace them with Allen head cap screws, torqued to about 60 to 80 inch pounds, use good gaskets, and you'll be on the road again.

    Check the torque of those fasteners after the engine has run a couple of times and you'll be enjoying your bike again.

    Oh, and while you're at it get rid of that kit spark plug boot and replace it with a good automotive quailty boot.

    Tom
     
    #3 2door, Sep 18, 2013
    Last edited: Sep 18, 2013
  4. mapbike

    mapbike Active Member

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    Engine looks good to me, just replace those acorn nuts with standard M8x1.25 nuts and as to the intake stud if the threads are a bit wallard out, get you a small tube of Red loctite thread locker, put a good amount on the stud, screw it back in good and snug and let it sit over night before putting intake back on and use blue loctite on the studs before you install the nuts back on to secure intake, those nuts need to be good and snug but remember they are only M6 studs and nuts so dont get crazy with them, just good and tight and let the thread locker do the rest.
    I'll bet that will get you up and running good again and prevent needing to buy a new engine.

    If I missed something here I apologize but just hate to see someone spend money and go to trouble that isn't necessary.

    Map.wee.
     
  5. mapbike

    mapbike Active Member

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    Dang Tom I posted and seen that we were pecking stuff out here at the same time.

    I should have just waited and let you handle this.....lol!

    Map
     
  6. Kioshk

    Kioshk Active Member

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    laff

    [APPLAUSE]
     
  7. CranbrookKid

    CranbrookKid New Member

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  8. crassius

    crassius Well-Known Member

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    those studs come in several diff threads - sometimes with interference threads at the top - be aware of this when you look for replacements or do re-tapping
     
  9. mapbike

    mapbike Active Member

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    My local Autozone auto parts store has these kits in stock but if you cant find it locally I'd say order one from here and install the thread inserts with some red loctite on them and if there is any thread at all left for the insert to grab onto you should have a good thread again for the intake studs or bolts.

    http://cheapmotorcycletiresdiscount...PY-M6_X_100_Perma_Coil_Thread_Repair_Kit.html

    map
    reddd
     
  10. CranbrookKid

    CranbrookKid New Member

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    Thanks for the advice everyone. I'll try and see if I can reuse the original studs. Most likely need new rings. Does anyone know where I can get upgraded hardware (head studs, intake+exhaust etc.? Pirate cycles had some but they are out of stock.

    EDIT: Nevermind found some at jn motor bikes
     
    #10 CranbrookKid, Sep 19, 2013
    Last edited: Sep 19, 2013
  11. fatdaddy

    fatdaddy New Member

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    I clicked on this because it said Huffy Horror story, Turns out it was a Exhaust stud horror story. I've been there a hundred times, Just tap it out to the next acceptable size. I"m suprised nobody suggested that you throw the huffy in the dumpster. I've been riding my Cranny for over 2 years , no problems with the bike. I had to replace the 2 smoke a while back.It was getting a little old and tired after 4 1/2 years of very hard riding. IF you get a new engine Replace all the studs before you even install it. Chinese quality control is a joke.
     
  12. crassius

    crassius Well-Known Member

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    if your old rings still have much of their original black coating on the outer edges, you should be able to reuse them
     
  13. 2door

    2door Moderator
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    This is a topic that needs to be out there more. Some, not all but a fair amount of engines come with cylinder/head studs that have fine and course threads. Usually the fine threads are on the case end and the course on top where the head nuts go. This has caused not a few problems for the inexperienced when they remove the studs then not noticing the different threads try to reinstall the studs and the result is usually stripped threads on both ends and lots of headaches for the builder.

    If you remove a stud check it carefully for the thread pitch on each end. The difference in the threads is noticeable. As Crassius said, they are 8mm x 1 for the fine thread and 1.25 thread for the course. And to repeat AGAIN, don't use those chrome acorn nuts; but the do make good slingshot ammo.

    Tom
     
  14. crassius

    crassius Well-Known Member

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    and the 1.25 threads may be straight threads on bottom and interference threads on top (interference threads have sharper edges on the thread or shallower grooves between threads making it drag a bit in the nut to help prevent vibration from loosening it). A new nut will go on one end easily, but stiffly on other end - put the interference thread up.
     
  15. CranbrookKid

    CranbrookKid New Member

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    It's not the exhaust studs that are ruined, it's the intake and the four cylinder studs. I think I will change most if not all studs.
    Thanks, I was wondering if I should have to replace them or not. I have to remember to check.
     
  16. mapbike

    mapbike Active Member

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    Ditto.......! 100%

    Map
     
  17. CranbrookKid

    CranbrookKid New Member

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    I just thought I'd update this thread. When I went to take the cylinder body off I noticed the cylinder walls were deeply scored, hence the smoking and no power. While the engine was apart, I took the liberty in ordering new studs from sickbikeparts. Great quality studs. I also ordered upgraded hardware which I should have done from the very beginning, a b8hs plug, puch head, new rings, cylinder body and all the gaskets that were needed. Now I'm just waiting on the cylinder body, so when that comes in, I'll take some pics. I named this thread a horror story because not only my exhaust studs but also my head AND intake studs AND rings AND cylinder body were damaged.
     
  18. mapbike

    mapbike Active Member

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    Best wishes on getting all together and having a solid strong engine when you're done....

    Map
    .wee.
     
  19. CranbrookKid

    CranbrookKid New Member

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    Thanks mapbike, I'm crossing my fingers.
     
  20. CranbrookKid

    CranbrookKid New Member

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    I put the bike together!!! The cylinder body I just got is cast quite a bit better, no jagged edges, but has a smaller intake so that stinks. It's also got slightly different shaped transfer ports, no idea if it's good or bad. I'll most definitely put the puch head on in the near future. First pic is before the rebuild. Another thing, the cylinder body had paint in it :eek: !!!? I removed it with a bit of gas. I've yet to open the head, I'll probably do that tomorrow.
     

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