First Time Buyer/Builder

Discussion in 'Photos & Bicycle Builds' started by twitch0601, Jan 15, 2015.

  1. twitch0601

    twitch0601 New Member

    So, after kicking around some ideas. I have finally made a decision to build a Motorized bike. I first wanted the GT2-a frame with a 4 stroke motor but im trying to keep costs down and im a little impatient and want to get my feet wet and see if this is something i really want to do or not.

    So right now i have a 2005 KHS DJ 100. Its a dirt jumper and i just measured the frame and it will fit a 2 stroke. I hope.

    I am looking at this kit on ebay and i just want to know if anyone has bought this exact kit before and if its a decent starter kit.

    Here is the link

    I am skilled enough to build a bike and a motor I just havent put them together. Any help will do. I will post pictures of my progress as well.

    Lastly, Is there another way to mount the motor on a bike with a larger downtube without the bracket?


  2. dougsr.874

    dougsr.874 Active Member

    Don't be fooled by the ads....all of these Chinese 2 stroke kits are basically the same.....A brand name means NOTHING..
  3. Ollie

    Ollie Member

    You'll need to use the adapter unless you can fabricate your own custom mount. You may have to get a larger frame.

    All the Chinese 2-strokes (with varying brand names) are pretty shoddy quality and need a lot of maintenance.
  4. Timbone

    Timbone Active Member

    That engine looks as good as any. I would be ure and get a 415 (motorcycle) chain. They are almost indestructable.

    Another thing: Motor mounts are key and it is best to over engineer them. Make it so your motor is straight and cannot move.
  5. twitch0601

    twitch0601 New Member

    Well I bought my first kit and it should be here by Friday. I'm going to be going through it and using the guided on here that help you before you install the motor.

    Does anyone happen to have a video on things that's should be done before installing your motor?
  6. KCvale

    KCvale Motorized Bicycle Vendor

    This will be a bit tricky...


    ... but it looks to be doable and I'd do it this way if that helps any.

    First you need to get an accurate diameter of your downtube and head over to

    Their 'muffler clamp' based inverted mount is what you want for the front.
    They have a Large size and Small size plate, start with the clamp sizes you can order with the Small size list.

    It will let the motor almost it on the frame and provide a strong 360 grip.


    You will most likely need an offset intake as well, but it's a tough call.

    That example bike has a bigger cavity than yours so you will want a front slanted plug.
    If it doesn't come that way, spin your head 180 degrees.
    I do 66cc head torque to 15# cold and after initial testing torque it down to 20# hot.

    While at SBP get yourself a dual pull brake lever, and for a cheap boost get an NGK 5944 (BPR7HIX) iridium spark plug.
    The 7 is the heat index, if you have snow get a 6 (BPR6HIX).
    And since you have lever/thumb shifters get the Grip Shifter for the appropriate # of gears too, 7 on that back sprocket?

    While you wait on parts you can start on the handlebars.

    In short you already have full handles and you need to add a full grip throttle and clutch lever.
    2 things need to go.
    In short, Strip everything off down to bare bars.

    1. You won't need a way to change what front pedal sprocket you are on from the handlebars with an engine, pull the entire front derailleur system and controller off and manually put the chain on the front sprocket you want.

    2. You can't work 3 pull levers at the same time and where the dual brake lever comes in.
    Ditch both bike levers and put the dual pull on the right before the throttle.

    That leaves room for the clutch lever and then a grip shifter for your rear gears.
    It's reading is upside down but it works great without looking.



    It doesn't matter what back gears you have, just that it is a rotary shifter.

    Last but FAR from least is the grips.
    I think I have only used like 3 kit grips on my last 80+ builds! They SUCK, even minimal vibration gets old after 1/2 an hour.

    I just cut the stock grips off the throttle barrel with a utility knife and pitch'em
    The throttle barrel grip is the tough one, it is fatter.

    For what you have just a package of BMX black foam bike grips will do the trick, it's what I use if the bike didn't have padded leather stitched grips that is.
    Those are soo cool.

    Anyway, just some things to keep in mind as you not just add a gas motor to your bike, but control it.
  7. twitch0601

    twitch0601 New Member

    Your awesome KCvale. Thank you for taking the time to type up everything to help me. I will check the fitting of the motor when it gets here and see if i will need any of those parts you listed. I will also be ordering the Dual Brake Lever. I have already converted the bike to a single speed, because i was using it as a 26inch BMX. So, i wont have to worry about taking much off the bars.

    My only question is that you said to torque the head down to what exactly. Cause it says 15# and 20#... Do you mean foot-pounds? or?

    Again thank you for your help. I will get some pictures soon....Once I Get the motor
  8. KCvale

    KCvale Motorized Bicycle Vendor

    You're welcome twitch.
    Foot Pounds.
    The manual says 15# but I find 20# when hot to be best on a 66cc.

    Just tighten a couple pounds at a time on each nut in a crossing pattern until they are all the same.

    You would get a kick out my torque wrench, it's as old as I am but still does the trick.
  9. Fly1

    Fly1 Member

    Ya KC is a good guy, & helped me a lot with my first.

  10. twitch0601

    twitch0601 New Member

    So I finally got my motor kit in the mail yesterday and it came way quicker than i expected. Here is a piture of my bike that i hopefully plan on installing the motor into.

    And a picture of the motor sitting in the frame.

    Now of corse I was very excited to go out and test fit the motor because I wasnt very sure it would even fit. And to my suprise....It didnt. Heres why. My downtube is just a tad too large as you can see in the picture.

    Also for it to fit with the carb i had to take off this part here...

    So now the motor just sits on the frame like this...
    Which i know is not good.

    And then theres the problem with the carb not fitting with the ait filter enclosure on it. and i had to take off the carb cable adjuster.

    Hopefully i can get some help on what to do or if i should just find another bike? All help is appreciated.

    But... I think I can make it work. Now tell me if this is wrong or wont work.
    Im sure if i grind down the downtube mount very carfully on the side so that it wont have a gap andymore. I can then make or buy another airfilter to fit, buy a 90 degreee cable adjuster and then cut down the part that goes on the studs for the seat post mount so that its not as tall, then everything will be good.... My main question is that if i grind the downtubes motor mount..will it make anything weaker or ???
  11. twitch0601

    twitch0601 New Member

    I forgot to mention also. I do know that there are front engine mounts that will allow me to make it fit rather than grinding the motor up, but the motor mount will take up more room. I also know that i can get a offset intake but im sure ill be ok with a low profile filter and the 90 degree cable adjuster.
  12. Timbone

    Timbone Active Member

    I would simply find another frame to work with. Why fight this? Besides, this bike looks small - I think 26" wheels are the way to go. One of the things I enjoy about riding my motorbike is to look down and see the big tire up front rolling.

    You can make a functional thin air filter, but it's gonna be a pain in the butt to take on and off.

    A big part of the fun of this is making it work so, if you are really determined, go for it. There are no rules.
  13. twitch0601

    twitch0601 New Member

    This is a 26inch bike. Lol. I guess it does look small but it's not. It's a really good bike and I am determined to make it work. I know it will work if I grind the motor mount a little so it sits flush. I just want to know if anyone has done that before and had it work fine.
  14. Caplain

    Caplain New Member


    Correction: The chains are absolutely indestructible :) You will damage your engine/wheel before those chains even chip.

    And yes make for CERTAIN your mounts are on nice and tight. A loose mount can lead to a bolt breaking off inside your block and that's no fun. On that note, don't use the standard sprocket mount either. Go all out. You'll save more on wheels in the long run
  15. fattirejack

    fattirejack Member

    Just do it! It's your ride, Make it happen. There may be several frames that are better suited for motorizing, but that's not what you have. I am building a Mongoose Beast fat tire bike, I was told the same thing (get a different frame). The Wright Brothers were told they couldn't FLY. The only limit is your imagination (or abilities),GO FOR IT. HAPPY MOTORING
  16. KCvale

    KCvale Motorized Bicycle Vendor

    Just take your carb and intake off, an off-set intake will fix that problem.

    You engine won't stay in place just butted up against the seat post.
    All your engines drive force is against the seat post and it has to be perfect.

    You might be able to cut ~1/4" off the engine side of the rear mount block but that's about it, put it in and go from there.

    Your front mount, besides helping to keep your engine from leaning, also keeps it from wanting to pivot to the left.
    If your front mount studs are hitting both sides of your downtube there won't be enough material to remove by grinding your engine front mount, you would have to go all the way to the studs leaving nothing to hold them in the motor.

    The best bet is a SickBikeParts front mount.
    It'll raise your engine some but doable I think.

    Is that a steel or aluminum frame?
    I don't recommend this a first option but if nothing else will work you can pinch a steel frame a little right where the engine mount will pass so the engine can rest in that front mount.

    I found a pair of heavy duty C clamps worked pretty well.
    Two clamps side by side tightened from each side until the tube elongates a bit.

    Just be committed to motorizing that bike before you do that ;-}
  17. Rebel Riders MB

    Rebel Riders MB New Member

    I run into the problem of having a fatter down tube than engine mount. it might not be conventional but i take my bicycle and put in a vice (with a cloth around it to prevent scratches). i squeeze the frame until its skinny enough to get the engine on there. I've never had any problems nor seen signs of weakening.
  18. twitch0601

    twitch0601 New Member

    Well Its been a little while since my last post because i ran into a few problems. I was able to grind the downtube mount just a little to make it fit perfectly. Im really glad i didnt have to put the frame in a vice, it was the last resort. I cut the seat post spacer mount in half and was able to bolt it to the bike. All the harware was changed and I torqued the head down. Did a few other things... Thats when the other problem happened. I wasnt able to put the sprocket on because my rim had disk brake mounts and the sprocket wouldnt go over it. So i ended up buying a new rim and finally got it all together.
    I have the clutch cover off cause i was adjusting the clutch.

    I think its looking good. I was barely able to get the carb on but its all good. I need to get a 90 degree cable adjuster for the carb. and a low profile air filter, also some better fuel line.
    I will also have to pick up a dual pull lever and eventually get the hub clamp sprocket mount.
    Eventually I will paint the Tank and Motor in a High Heat Flat Black.

    What do you guys think? Is there Something i should do or something that would make it look better?

    Thank you to everyone who helped me with there knowledge.
  19. KCvale

    KCvale Motorized Bicycle Vendor

    Sweet, and you're welcome.
    Some cosmetic cabling and wiring work and you have yourself a sharp bike.

    Bummer about sacrificing the disc brake though.
  20. twitch0601

    twitch0601 New Member

    I am a little bummed about the disk brakes but I never used them. It rode very nice, I was worried about there being alot vibration, but there wasnt any at all.