49cc 4 stroke huasheng gearbox/clutch bell issues?

Discussion in 'General Questions' started by joshua97, Oct 14, 2013.

  1. joshua97

    joshua97 Member

    please help. i have a 49cc huasheng 4 stroke chaine drive kit, for thus is the second time this has happened but on a different kit, i was riding then i loose power but motor revvs fine, i remove the gearbox (makes a clunk) and the clutch bell is all wobbly, i cant remove it thought as the bolt in the centre spins... i assume the bolt shaft snapped? the first time it happned the bell as wee as bit of broken bold in the bell snaped clean off, so do i need a new clutch bell? its really only the bolt/shaft i believe but how do i remove the shaft/bolt? basically i have a wobbly and loose clutch bell that spins freely and wont get power to the chains etc, and wont unbolt off either? please help me thanks josh

  2. HeadSmess

    HeadSmess Well-Known Member

    clutch bell should spin freely and be connected to rear wheel via chain/gear.intergral with gearbox. if its the box i think it is, you should see a 12-13mm nut inside the bell. that isnt the issue. or you wont achieve anything by undoing the nut at this point.

    you should be able to remove the box from the engine by undoing 4 bolts.check with a screwdriver by levering them, that the clutch shoes will move. if so, the clutch is fine.

    now the issue is the box.

    spinning the clutchbell should spin the output sprocket at 3:1 redux. or similar. but it will be a solid connection. once, again, if its the box i think it is. if nothing happens, its dead. if you saved your money and bought one good kit instead of two or now it will be three cheap kits... this wouldnt happen. (or 4 or five as you said elsewhere)

    split the box itself open, and...either its the chaintype and the bearings/bearing bosses have failed, or its the geartype...same deal. a gears busted a key, a tooth, sheared a shaft... somethings broken. the cheap gearboxes always break and sound rough when they do work.

    if its a chain type redux...get the gearbox from a 49cc mini dirtbike. the ratio is the same, the box is the same, but theyre made a lot stronger than the ones i see on the 4stroke kits.

    the splined output shaft and finding a suitable sprocket is tricky. i have to bore a HT sprocket, and turn down an old splined sprocket and weld them together... or change the rear sprocket and chain to suit the finer pitch chain. #35 on some, #25 on others...

    if its a gear drive type...save your money and get a real gearbox this time. search threads. the best types are named regularly.

  3. joshua97

    joshua97 Member

    thanks HeadSmess, it used double chains inside, the thing is the clutch bell just freelysins, is there a key o it that may brake? how to i remove it when the bell just wobbles and freely spons and alos the bold thust turns when i lock the bell? and so i can use a single chain 49cc pocket bike gearbox? is it the same sized clutch bell? and i could just weld my 10t gearbox sprocket to the smaller sprocket on the pocket bike trans? thanks
  4. HeadSmess

    HeadSmess Well-Known Member

    double chain? as in, two seperate chains, or a double (duplex) chain?

    hmms. if the bell just spins and is not driving the primary sprocket inside the box..

    what it sounds like is a stripped thread.

    by locking the sprocket (and shaft) you should be able to remove that nut.

    then, you should be able to remove the clutch bell. it should be screwed on to the shaft, the nut simply locks it so it wont undo.

    either the bell thread is stripped, which isnt that big a deal. a helicoil is the best bet, as...

    they just retap and thread in. is either m8 or m10.

    (hey, the threaded hub where its welded to the bell may have busted...youll find out if you look at it long enough ;))

    if the shaft is stripped, its a bigger issue. ive so far found 3 different types of shaft, depending on box.

    you need to do some searching for the correct part or get it made...

    welding sprockets all depends on the sprockets/skills. is it solid, is it freewheeling, will it be true when done? i machine em to a press fit.
  5. hazmat

    hazmat New Member

    just take your gearbox off and weld that bolt to the clutchbell so it dont spin anymore
  6. skyash

    skyash Active Member

    $15 pocket bike gear box fits straight on everything will fit .but some boxes are like 1mm longer so you might need to re adjust your chain .