Going to buy a bike kit

Discussion in 'Motorized Bicycle General Discussion' started by Donbia, Mar 4, 2012.

?

buying a bike kit

  1. low cost

    2 vote(s)
    66.7%
  2. outside the kits

    0 vote(s)
    0.0%
  3. better and cheaper engine ie: harbor fright

    1 vote(s)
    33.3%
  4. being able to do my own setup.

    0 vote(s)
    0.0%
Multiple votes are allowed.
  1. Donbia

    Donbia New Member

    Joined:
    Mar 2, 2012
    Messages:
    54
    Likes Received:
    0
    I am new to this blog, but I am trying to decide what kind of course to take buy a kit or a engine and do it from scratch. I have worked as a mechanic for more then 25 years as well as a machinist so ether would not be a problem, it seems a kit would be the low cost way to get started, but then there is the factor of be able to select the better engine and set it up for the way I want the bike to preform. Any opinions on this.
     
    #1 Donbia, Mar 4, 2012
    Last edited: Mar 4, 2012
  2. Mike B

    Mike B New Member

    Joined:
    Mar 23, 2011
    Messages:
    2,256
    Likes Received:
    2
    I would do a kit and a cheap bike first.

    That way you will get to learn how this stuff goes together, have some fun and not have to worry about scratching stuff up.

    Then, go do whatever custom bike you want.
     
  3. ddesens

    ddesens New Member

    Joined:
    Jun 27, 2011
    Messages:
    173
    Likes Received:
    0
    I agree with Mike B. Get a kit first and try it on a cheap bike. You will learn how it all goes together and how it feels to ride it. Then go from there.
     
  4. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    I also agree with Mike B & ddesens

    I've built go karts from scratch and several other things in the past, but I got a kit for my first motorized bikes.

    The kits are a good place to start, and then after you get it installed, broken in, and then fine tuned, you can start figuring out what mods you want along the way, probably better tensioner set up for chain if you even decide to use one at all, carbs on the engine are all jetted way rich so the jets always need to be soldered up and redrill for the engines to run right....Blah Blah Blah.....and so on, but there is a lot to learn and do with the kit engines and hardware, plus the kit will get you up and going pretty quick, then that bug will have bit the crap out of you most likely and there will be no looking back, you'll be hooked solid like most of the rest of us are.....

    Spend a couple 100 bucks, get you an inexpensive mountain bike or beach cruiser and you can be up and going in one day easy.

    The PK-80 kit that Pirate Cycles has right now would be a great place to start in my opinion.

    Best wishes with whatever you do.

    Map
     
  5. Rocky_Motor

    Rocky_Motor New Member

    Joined:
    Nov 14, 2011
    Messages:
    367
    Likes Received:
    0
    To learn, the best is probably a kit. You'll also quickly learn that almost everything in the kit is suggested to be replaced. NGK spark plug, better cdi wire and cap, new throttle+kill switch, better sprocket mounting method (depending on your situation)... But most of all, get rid of the included tensioner as fast as possible. Or modify it. More often than not, the tensioner will slide into the rear wheel spokes because it can't clamp properly. These engines can pose a lot of problems, but from a learning perspective you'll learn a lot from it. Some people here suggest taking the top end apart (head and the jug) and making sure that there is no junk ontop of the cylinder. I personally did this and found gasket material on top of my piston. It was also a great opportunity to re torque the head bolts.
    And finally.. I would say blue thread locker is a must. You'll have bolts rattlin loose all the time without it and then potentially breaking studs. Of course there is a certain torque range where you may not need the threadlocker but I personally do not know what numbers those would be.

    If you're confident in what you can do in terms of fabrication, you may feel up for getting a different motor. Mounting the motor is the hardest part most of the time for any engine that is not a "china girl" as it is called in these kits.

    Certainly is fun. Now that I have put my kit together and have found that the steps I took have created a reliable bike, I plan on stepping it up this summer with a new build using a real engine with 9hp. Either dax's or a morini.

    Good luck!
     
  6. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1

    DANG....! Rocky_Motor You make it sound like these kits are not worth messing with at all.........LOL!

    You do make some good points here, but the chain tensioner isn't a problem to secure at all, I've put over 1000 miles on the stock tensioners with out a single hitch if it is secure correctly by drilling a small hole through the tensioner bracket were i saddles the frame and continue the small hole into the frame just on the outside part of the tube and then insert a small sheet metal screw and it wont go anywhere.

    I still run the kit supplied throttles on all my bikes, haven't had a failure yet, but you're right they are lite duty, but hold up pretty good as long as you don't get rough with them.

    You're dead on the money about using blue loctite on everything, I also upgrade all the mounting hardware to grade5 6mm stuff and use cap screws for all the engine covers.

    I figure it's a good plan to just count on spending an extra $5 - $25 on hardware and possibly a couple other upgrades on top of the kit price, my first build didn't get any upgrades other than better rear mounting studs until I had about 1200 miles on it, rear studs are the only thing that ever failed, so I replaced them after 2 years of running this bike they haven't been touched since.

    I know there are better engines out there like you mentioned but for the money if someone knows what they are doing these china girl are a good deal and cheap and easy to maintain, oh and did I mention lots of fun......! (^)

    Peace, Map

    Here is one of the ways I set up the kit tensioner bracket, this thing is bullet proof, I make the tensioner rollers up myself, which are much better than the kit supplied ones but not neccesary to have, just an upgrade down the road.

    [​IMG]
     
  7. Rocky_Motor

    Rocky_Motor New Member

    Joined:
    Nov 14, 2011
    Messages:
    367
    Likes Received:
    0
    haha yeahh I don't mean to make it seem like the kit is worthless, it's just what I have read from other people on the forums. I suggested the throttle just because mine broke pretty quick. Although funnily enough my engine works better than ever because I can set the idle now. Longish story... Buut you're right, it's not all that bad. A lot of it is stuff that can be upgraded over time as one sees fit.

    That tensioner looks nice! Maybe you could make one like it that uses a spring instead of the long arm. Although I'm sure works great just as it is.

    Lots of unique fabrications can be done which is one of the great things about these bikes :D
     
  8. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    That tensioner looks nice! Maybe you could make one like it that uses a spring instead of the long arm. Although I'm sure works great just as it is.



    Yeah, I tried the spring set up, with this and it didn't work well at all, I figured out later how I can make it work by adding a stop to the arm that is spring tensioned so that when starting engine it doesn't over extend and throw a large amount of slack in the chain causing it to come off.

    If a bike has a pull start and the spring tensioner is setup right that would be OK, but I find that the rigid Idler/tensioner set up is the most trouble free if a person is gonna run an adjustable idler/tensioner at all, I have never had a chain come off of one of my bikes accept when I had the spring loaded tensioner and I have a combined milage of around 2,700+ miles on them, I live in the country and ride mainly on rough old dirt roads and I have zero chain issues with how I have mine set up, my other two bikes just have the basic kit bracket with one of the HD Rollers I made made up and put on them, they have no extra bracing at all and one of them doesn't even have a screw through it because the bike frame where it mounts is oval instead of round so there isn't any way it can rotate on the frame as long as the bolts are tight.

    There are several thing that have to be considered when using the kit parts, many times it all depends on the bike it is being used on, which will determine what mods may need to be done. each bike has it's differences and in my experience that will dictate what one needs to do to make it work out to be fairly trouble free/reliable.

    Everything one needs to know can be found on this forum, and that is what makes this community so valuable for us all in my opinion, a whole bunch of really smart, creative and just overall great people hang out here.......

    Peace, Map (^)
     
    #8 mapbike, Mar 4, 2012
    Last edited: Mar 4, 2012

Share This Page