Engine for a generator

Discussion in 'Motorized Bicycle General Discussion' started by pengyou, May 5, 2011.

  1. pengyou

    pengyou New Member

    Joined:
    May 5, 2011
    Messages:
    5
    Likes Received:
    0
    I have an electric scooter and would look like to put a small generator on it. I have not found anything of reasonable size and weight so I am looking into the possibility of putting my own together. I have found some electric radio control motors that would work to generate electricity. Now I am looking for a small (35-50cc), lightweight compact 4 stroke engine to connect to the electric motor. Durability is also important. It will be running at virtually a constant speed.

    Any suggestions?
     
  2. moonshiner

    moonshiner New Member

    Joined:
    Apr 23, 2011
    Messages:
    199
    Likes Received:
    0
    there are no real cheap 35 to 50 cc 4 stroke motors , the cheapest is the huang Seun or however its spelled , they range from about $179 to $ 250 , myself i would put down some extra cash and buy a subaru or a honda 35 cc motor ...cs.
     
  3. corgi1

    corgi1 New Member

    Joined:
    Aug 13, 2009
    Messages:
    2,282
    Likes Received:
    1
    Or an old lawn mower engine if only making a generator
     
  4. pengyou

    pengyou New Member

    Joined:
    May 5, 2011
    Messages:
    5
    Likes Received:
    0
    Thanks! The price is certainly a consideration but right now I am looking at size - compactness, and weight. I have even considered a gas powered radio control motor used to fly airplanes. They have some that are 50cc+ and a few that are 4 stroke, though oil still has to be added to the fuel - no crankcase. Weedwhacker engines tend to be compact also and only about 7 pounds...so..please continue with your suggestions. I am really trying to think outside of the box here :) FYI I can get a "huang seun" here for about US $80 There is also a factory in the south of China that makes the little Hondas...they also will make the same engine and sell it under a Chinese name. I trying my best to find that brand.
     
  5. moonshiner

    moonshiner New Member

    Joined:
    Apr 23, 2011
    Messages:
    199
    Likes Received:
    0
    for $80 , that's cheap , i would just go with the 50cc HS 4 stroke , i forgot you were in shanghai , you can probably find every thing you need very cheap just laying about ..

    Keith
     
  6. Erich_870

    Erich_870 New Member

    Joined:
    Dec 4, 2009
    Messages:
    78
    Likes Received:
    0
    This is probably the most cost effective 4 stroke you'll find in the US: Ryobi ZRRY34420 30cc 4-Stroke

    They sell just the power head, but I haven't found one that beats this amazon price.

    Erich
     
  7. wheelbender6

    wheelbender6 Active Member

    Joined:
    Sep 4, 2008
    Messages:
    3,816
    Likes Received:
    10
    The small, 2 stroke generators still weigh 40-50 lbs. Tough question.
     
  8. pengyou

    pengyou New Member

    Joined:
    May 5, 2011
    Messages:
    5
    Likes Received:
    0
    Hmmmm the weedwhacker has potential. As I understand, a generator is simply a gas engine hooked up to an electric motor (simplified). The weedwhacker engine is about 10 pounds. If I connect it to an r/c electric motor (same model as I will be using to power my ebike) the total weight would be about 17 pounds. I am guessing that the weedwhacker will work well at about 7,500 rmps, which is about 3,000 more than the motor on my bike will be turning. How long can I expect the weedwhacker to last if run in a constant speed mode with good filtered fuel and a synthetic oil? 500 hours? 1000 hours? Is this something that could be rebuilt - new piston, rings, bearings, etc or is it something that CANNOT be rebuilt? Please note - I am not consider the cost of rebuilding or replacing. I hope to make my ebike a land yacht and cruise through parts of China that would probably not have a 35cc gas engine available, so rebuilding would be the most convenient option if it started to lag. Would a Honda weedwhacker motor be more reliable? Can I get a better carburetor for this or other things to improve the performance and reliability? What if I want to go up a step and get a 35-50cc engine with a starter? Still, if the weedwhacker is connected to an electric motor to generate electricity, I can use the electric motor in "motor mode" to work as a starter for the weedwhacker engine. Lots of questions here :) I hope to implement this in the summer but I have to make some decisions now about how to use the space on my ebike. I want to buy the lithium batteries now - at US$ 400 an expensive proposition - and i won't be able to change my decision after I make it. The batteries come in a variety of shapes.

    Here is a pic of a bike like me, just so that you know what I am beating one :) http://item.taobao.com/item.htm?id=9945325151
     
    #8 pengyou, May 7, 2011
    Last edited: May 7, 2011
  9. corgi1

    corgi1 New Member

    Joined:
    Aug 13, 2009
    Messages:
    2,282
    Likes Received:
    1
    How does the oil level work on a 4 stroke weed wacker,it is held at various angles and oil level would change a lot???
     
  10. Goat Herder

    Goat Herder Gutter Rider

    Joined:
    Apr 28, 2008
    Messages:
    6,250
    Likes Received:
    2
    Giro-scoping Conuiter Valve. ;)
     
  11. corgi1

    corgi1 New Member

    Joined:
    Aug 13, 2009
    Messages:
    2,282
    Likes Received:
    1
    GH do you know a site that shows the exploded/see-through view of a WW 4 stroke,I clicked a bunch on google but none the pic results I needed,I want to see that giro-scooping part
     
  12. wayne z

    wayne z New Member

    Joined:
    Dec 5, 2010
    Messages:
    1,746
    Likes Received:
    0
    Maybe you could try a locomotive style drivetrain.
    They use a large diesel gennerator to power the electric motor driven wheels.

    They use the throttle on the generator to control wheelmotor's power and speed. Very simple system with minimal circutry to engineer.
     

Share This Page