I think I'm back

Discussion in 'Introduce Yourself' started by alesterfeind, Jun 15, 2014.

  1. alesterfeind

    alesterfeind New Member

    I was on here several years ago, but then sold my bike have moved a few times since. I want to do another build again, and start riding. I live in Flower Mound, Texas.

    Is anyone familiar with this engine kit distributor?: http://bestbikeenginekits.com/index.php?main_page=index

    Seems like a good price, but I don't want to buy crap.

    Since it's been so long since I have bought a kit, does anyone have a recommendation of a good dealer?

  2. jaguar

    jaguar Well-Known Member

    since vibration is a major problem with the chinese 2 strokes I think you should try out one of the "balanced" kits they offer
  3. Fabian

    Fabian Well-Known Member

    No such thing as a balanced single cylinder engine, unless it uses balance shafts.
  4. jaguar

    jaguar Well-Known Member

    I am speaking in relative terms, not absolute terms.
    "balanced" with a 2 stroke means it doesn't annoy you with excess vibration.
    the stock Grubee engine is worse than annoying but can be mostly fixed.
    Although you have a vibrating engine and have learned to live with it Fabian please don't try to masquerade your laziness to fix it behind your statements that perfect balance cannot be had in a 2 stroke.
  5. Fabian

    Fabian Well-Known Member

    Perfect balance (and even semi-perfect balance) "cannot" be had in a single cylinder engine, be it a 2-stroke or a 4-stroke, regardless of how much you like to believe your religious philosophy on this subject.

    The most effective method of reducing the intensity of vibration is to improve low and midrange torque and then operate the engine in that lower rpm zone.
  6. Ironhorse

    Ironhorse New Member

    Wow... Can't anyone just answer the guy's question? Ie Is that kit/dealer worth a crap not?
  7. jaguar

    jaguar Well-Known Member

    I don't care how good a dealer is if they are selling unbalanced engines.

    Fabian, I am not even talking "semi-perfect". I am talking "minor vibration" , something that is not bothersome.
    For example my Suzuki 100 has almost completely undetectable vibration at cruising speed but slightly annoying vibration at some other speeds with full throttle. This is a good example of a balanced engine. "balanced" is a relative term when it comes to 2 strokes.
  8. Fabian

    Fabian Well-Known Member

    Every dealer selling single cylinder engines (without a balance shaft) is selling unbalanced engines, because as has been discussed many times before, a conventional single cylinder engine cannot be balanced through a 360 degree cycle.

    This example could almost be seen as a disingenuous example because the motorcycle (less the weight of the engine) is significantly heavier than the engine itself; giving some level of "mass" dampening.
    By the numbers, the Chinese 2-stroke engine is almost as heavy as the bicycle it is being affixed to, which is why vibration is so effectively transmitted through the bicycle frame; and is also the very reason why rubber mounting the engine to the bicycle frame does not give any vibration dampening effect.

    No, your Suzuki 100 postulation is a bad example with respects to inherent mechanical balance for a single cylinder engine.
  9. Fabian

    Fabian Well-Known Member

    I sent the vendor an email and received an honest reply, which differs from the product specifications.

    These are pressed together, not technically one piece, just the way China markets them. They are not held together by screws, they are overall much better balanced and run smoother than your typical eBay engine. I don't have pictures other than the one on the website.

    At the end of the day, the vendor's engines use the same technology that just about every other manufacturer of these engines currently produces.
  10. butre

    butre Well-Known Member

    [​IMG] the picture quality isn't great, but it's good enough. I don't know if it's better balanced or not but at very least it's prettier.
  11. Fabian

    Fabian Well-Known Member

    Since i got into this method of transport/hobby 4 1/2 years ago, all of the engines and replacement crankshafts purchased from my vendor have only used the design as shown on the left hand side of the photo.

    The biggest improvement to reliability has been the adoption of crowded needle roller "big end" bearing design; also known as a full compliment bearing design.