Looking for help!

Discussion in 'Motorized Bicycle General Discussion' started by AmazingAarvark, Jun 1, 2015.

  1. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    To start off, I just bought my very first motorized bicycle kit, and I love it. Here is a link to look at it if you want.

    http://www.ebay.com/itm/Fantastic-4...Gas-/321344019046?hash=item4ad1989a66&vxp=mtr

    After putting it on a Walmart-special "mountain bike", I took it for a ride. It runs, but since it's just a cheap Chinese one, it doesn't have much power.The problem I have is that I have no idea how to make it run better. I don't know how to tune it and make sure everything is balanced, and I don't know what after-market parts I could install to help it.
    It can't accelerate on a slight incline, and you can forget about doing hills without pedaling your butt off. I don't have a speed gauge, but on flat ground, it seems to do about 10-15 mph. I've done some reading, and it seems I should have more power out of it. What should I do? By the way, I'm a 6'2" and 185lbs, so there isn't too much of a load. Before I forget, I'm super excited to have joined the forum. I've looked through many of the posts here, and you guys seem to know your stuff. Thanks
     
  2. crassius

    crassius Well-Known Member

    Joined:
    Sep 30, 2012
    Messages:
    3,568
    Likes Received:
    59
    first, you need to run the motor in for a while to get more power

    while running it in, you might want to drop your needle lower to lean it out - NOTE it will get leaner as it runs in, so check your spark plug to be sure you don't go too lean
     
  3. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,909
    Likes Received:
    82
    First welcome to the forum, in my opinion you probably need to get the engine broken in first. About three full tanks of fuel should be good. A free flowing exhaust helps the most on just about everyones build, a modified stock pipe helps with a SBP expansion chamber being better. Some members have built custom chambers taylored to their engine that maximizes the power delivered. A nice replacement air filter might not help performance but do a better job than the stock filter, I have a SBP filter that I like a lot.
     
  4. xseler

    xseler Well-Known Member

    Joined:
    Apr 14, 2013
    Messages:
    2,778
    Likes Received:
    53
    Howdy & welcome to the site!!

    If you're using the 16:1 fuel mix that is 'recommended', that's way too much oil. Most folks on here use 24:1 or 32:1 for break-in. That in itself will help to increase your power. Just make sure you're using a good synthetic oil (& not one designed for outboard boat motors). Your engine will love you for this.

    After the break-in period, you'll probably want to rejet your carb to a smaller orfice. There's multiple threads on here concerning this issue.........many opinions, just read up and you'll start to see some common themes that create the most success.

    Best of luck in your new adventure!!
     
  5. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    Is the "needle" the needle-looking thing that is right below where you attach the throttle wire?
     
  6. xseler

    xseler Well-Known Member

    Joined:
    Apr 14, 2013
    Messages:
    2,778
    Likes Received:
    53
    I'm already seeing some common themes.....dance1
     
  7. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,909
    Likes Received:
    82
    My avatar is my bike which has a 48cc engine, mine will do 31-32 mph on flat ground. I'm in the 210lb range, I run a 44 tooth sprocket that helps low end but limits top end. I also have a eBay engine that runs well after broken in.
     
  8. xseler

    xseler Well-Known Member

    Joined:
    Apr 14, 2013
    Messages:
    2,778
    Likes Received:
    53

    Yep. Many have found that the 2nd notch from the top is the optimal position for the cir-clip.......
     
  9. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    Thanks, I was using 16:1. I'll fix that on the next tank.
     
  10. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    Could you please explain "free flowing exhaust", "modified stock pipe", and "SBP expansion chamber." I'm not only new to motor bikes, I'm new to engines and technical stuff in general. Thanks, u-da-best!
     
  11. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    Thanks man! I'll try that.
     
  12. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    You sir, have given me great hope. I thank you for it.
     
  13. AmazingAarvark

    AmazingAarvark New Member

    Joined:
    Jun 1, 2015
    Messages:
    8
    Likes Received:
    0
    Also, what is a good ratio for when the engine has finally been broken in?
     
  14. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,909
    Likes Received:
    82
  15. xseler

    xseler Well-Known Member

    Joined:
    Apr 14, 2013
    Messages:
    2,778
    Likes Received:
    53

    This question has caused much turmoil......lol! There's many opinions --- ranging from 20:1 to 100:1 (100:1 only with Opti 2 oil). I use 50:1 Echo oil.....mainly 'cause I use it in my weed whacker. 10 years so far on the whacker and 100's of miles on the bike. It's what I'm comfortable with.

    With 50:1 Echo oil...

    [​IMG]
     
    #15 xseler, Jun 1, 2015
    Last edited: Jun 1, 2015
  16. Greg58

    Greg58 Well-Known Member

    Joined:
    May 1, 2011
    Messages:
    2,909
    Likes Received:
    82
    I run Lucas simi-synthetic at 32/1, I was running at 40/1 but my tune seems to work best at 32/1. You'll learn a lot about tuning later as you read posts by the more experienced people here.
     
  17. Slogger

    Slogger Member

    Joined:
    Sep 8, 2014
    Messages:
    545
    Likes Received:
    3
    Welcome-
    After break in a 32/1 mix will run just fine, plenty of lubrication without fouling spark plugs.
    As a newby without any idea about the engines, I think the very best thing for you to do is to read read read this forum. Everything you wonder about has been talked half to death on here at some point.
    Develop an understanding of your engines fuel and ignition systems, air/fuel mixtures and oil/fuel mixes before you go changing things or dremeling out ports and whatnot, and your bike will thank you for it.
    Get it solidly mounted, get the chain lined up perfect as you can, watch for air leaks and loose cylinder head, read this forum, and you should do as well as anybody with the bike. Feel free to ask any questions but be as thorough and specific as possible so people give you their best answers..
    and Good luck!
     
  18. Davezilla

    Davezilla New Member

    Joined:
    Mar 15, 2014
    Messages:
    2,708
    Likes Received:
    3
    Welcome to the forum...
    From reading the other posts in here it looks like you got the advice you need... first off, you need to run in your engine, it will go faster and run smoother as it breaks in, change your mix to at least 24:1 or 32:1, both are safe for break in and it will also start a lot easier with the leaner oil mix. If you do experience hard starts when cold, check your plug gap and set it .022 to .026" these ignition aren't very strong at low starting rpm so closing the gap a little will help it start better and prevent misfires when running.
    Don't worry too much about carb jetting during break in since you want it to running rich during this time to help prevent overheating, removed jetting the carb is best done after at least mthe second tank has run thru.
    Check your head studs after its run several times and return torque as necessary, these will work loose a few times but stay put after it runs in more. If you do feel it start to feel a little sluggish and lose some power during this time kits time to let it rest and cool down, I try to keep the first several runs under 10 minutes while breaking it in, but run it like I intend to after break in, just keep running it up and slowing down to run it up again to help seat the rings, you can ride it hard but don't linger at top speed or at any constant speed during the first tank, when you feel it start to lose it's edge, it's time to stop and let it cool down so stay close to home the first several runs.
    when the engine is cooled down, check that the head nuts are still tight (120 to 140 in/lb) use a torque wrench since these are easy to overtorque. Also periodically check the intake and exhaust bolts and the case bolts that can be accessed. Mount the engine very solid to the frame and check that the hardware don't work loose. Check chain tension and alignment frequently until everything stays put and your bike will thank you.

    After the engine has been run in thru at least 2 full tanks of fuel then you can start tuning the carb or replacing with a performance like the RT carb. You can remove the end cap off the muffler and drill at least 3 5/16" holes thru the end cap for more performance without making it too loud during break in and modify or replace the stock exhaust after it's run in some more, an aftermarket air filter will also help during break in and after.

    If you want more speed or power after break in, do a LOT of reading on porting before you attempt, and feel free to ask as many questions as you need before even looking at a dremel, we will help.... mine would barely go past 25mph when new and I've got it up to 42mph thru the stock nt carb and with the stock 44 tooth rear sprocket and so have quite a few others so we can help you get there once you put some miles on your engine.
     
  19. LandSpeedRecord

    Joined:
    Dec 11, 2014
    Messages:
    604
    Likes Received:
    0
    First thing, welcome to the forum. You already have some great advice from some very knowledgeable people on here. The most important of which recommends read, read, read, and read some more. Every single piece of your motor has been discussed, studied, and tested on here in great detail many times over. That being said searching and being confident you found the correct information and applying it can be intimidating when you are new. Feel free to pm me anytime I am glad to help when I can or at least direct you to the correct info. Happy Motoring!
     
  20. 2door

    2door Moderator
    Staff Member

    Joined:
    Sep 15, 2008
    Messages:
    16,304
    Likes Received:
    29
    Welcome to the forum. You've recieved some valuable advice from some of our most experienced and respected members. If you need more help, ask or use our 'Search' feature where you can find answers to most any question. Nevertheless we're always here to help if you need us.

    Good luck, have fun and ride safe.

    Tom
     

Share This Page