Bad Vibration Not Good Vibrations.Lol

Discussion in 'General Questions' started by john morrow, Sep 20, 2016.

  1. john morrow

    john morrow Member

    IMG_20160914_155442~2.jpg Any advice on how to minimize vibration would be helpful..

  2. zippinaround

    zippinaround Active Member

    Try jags spoke test , hold something long and thin against the engine like a spoke slowly rev up and watch for the spoke shaking but my guess is you will have to balance the crank
  3. crassius

    crassius Well-Known Member

    motor mounts are the usual cause of vibration - if rubber is used there, it will shake itself apart
    Christopher Kelly likes this.
  4. john morrow

    john morrow Member

    You are right about rubber I would never use it. I read about people using leather, anyone have any thoughts?
  5. jaguar

    jaguar Well-Known Member

    these engines are designed with multiple problems to limit speed so they can be approved by more governments.
    You have to take the crank out and balance it. see
  6. zippinaround

    zippinaround Active Member

    Best used a hard mount rubber , leather or anything softer then the engine won't work.
  7. john morrow

    john morrow Member

    Thanks Jag for all the info I will let you know how it turns out.
  8. crassius

    crassius Well-Known Member

    I like to use a piece of PVC on rear mount, and if needed, some as spacers on front mount. It settles in pretty quickly. I've used leather and it is good, but it needs a lot of tightening over time as it compresses into a good seat.

    Sometimes moving the rear mount up or down just 1.4 inch can make a diff in vibration, and note also that if it is 4-stroking a lot before it runs in that can make is seem much less smooth.
  9. john morrow

    john morrow Member

    Are you talking about using PVC pipe? Please explain how you use PVC?
  10. crassius

    crassius Well-Known Member

    cut it so that it is in "C" section and put it between frame and rear mount - it will squeeze down to make perfect fit

    a pic of how mounts look would be nice
  11. oliverw123

    oliverw123 New Member

    My 48cc engine clocked up around 25000km and was perfectly smooth throughout the rev range. I only rode it one way and that was throttle wide open, I had it screaming most of the time and could easily get up to 65km/hr. All was good until I drove one of our trucks over it, don't ask. The bicycle was mangled but the engine was fine. I did a complete strip down and I was amazed to see how the internals were still in top notch condition, after all those years and kilometers. My mix was 50:1 using high quality 2-stroke oil.

    I recently installed a 66cc engine and man that thing is un-rideable. Being used to the 48cc engine, I normally wind them up but not this one, as everybody has mentioned, they vibrate like hell. It is a tractor though and it pulls my tool trolley around the yard very easily and as long as I use itjust for that, it seems ok.

    So these engines are highly reliable if you keep your hand on it. I never had a break down with my 48cc setup and would complete 100km round trips just for fun. Unfortunately I can't find parts for the 48cc kit anymore, locally that is.
  12. HumanPerson

    HumanPerson Guest Speak to Duane.
  13. Tighten your motor mounts, first sign of a dangerous problem is a lose motor mount you might be able to use a inner tube on the mounts to absorb the vibration maybe bikeberry has a rubber insert another thing it can be your motoro bushing and so on that are cheape above 21MPH causes vibration a WildCat Motor that California Bike brags that his motors are smother due to using a pin rather than stock reduces vibrations above 21MPH you might want to flip hundred dollar bill on one of his motors if its a big problem.
  14. Frankenstein

    Frankenstein Well-Known Member

    Rubber mounts aren't a good idea, take up space, money, and make vibration problems worse (more flex at the mounts)

    If you have an engine that vibrates too much then your mounts are too loose or your engine is an unbalanced piece of crap.