Starter bike

Discussion in 'General Questions' started by Jessup, Sep 8, 2016.

  1. Jessup

    Jessup Guest

    Im looking to put an engine on my bike. I see all these kits available but at the same time dont want to waste money on a crappy engine. I primarily want it for transpo cause my job is nearby and i only have one vehichle for me and my girl. But at the same time i want something thats gonna be fun and quick. Im 200 lbs just curious what my best options are.

  2. Chopper bicycles

    Chopper bicycles New Member

    stay away from those 2 stroke kits they work but they suck bad in my opinon i got a motor from agri supply has 3 year warenty very powerfull,has pull start,much better quilty
  3. skyash

    skyash Active Member

    Yeah but if a 2 stroke gets 500kms for $100 its worth it not even $1per km .and if its your first build then its perfect. But i would not spend over $100 for one because at the end of the day the 66cc and the 142f are just toys .a ktm 50 is $399 and a rs 50 is $600 and holds the world record in its class. If you got one of them then everything around it is shit .get what you pay for.
  4. Steve Best

    Steve Best Active Member

    Hey Jessup, I weigh 210 lbs and live 45 kms round trip away from my office. I'm using a Grubee Skyhawk 66cc and a Grubee 48cc motor to get back and forth. I pretty much destruction tested the 66cc with increasing the speed to over 60kph (10,000rpm!) and still managed to get over 1000 miles on it at those speeds. I am enjoying my 48cc motor at more enjoyable and reasonable speeds of 30-40 kph. The 66cc still runs and runs fast by the way.

    Last weekend I met a guy who rides 100-200 kms a day on his Skyhawk. He has been riding them for years and has thousands of miles on several of these motors. He was geared heavy for touring too. These motors can be very reliable if you know what you are doing.

    So you have:
    $225(cdn) Grubee or other "China Girl" 48 or 66cc motor. Adds 25 lbs to the bike, gives 25-35 mph speeds and 100mpg(US) needs oil mixed fuel.
    $375(cdn) 4 stroke 49 or 55cc Honda clone. Adds 50 lbs to the bike, 25-35 mph speeds and 150mpg(us) needs oil changes.
    $500(approx) Honda or other quality engine and install kit, 25-35 mph speeds and 150mpg(us) needs oil changes.
    $600+ KTM 50 or clone, 35-45mph speeds, mechanical skills needed or stuff will happen, mixed fuel, expensive to repair.

    I think the answer is simple.
    Buy the cheap China Girl, read the manual, learn all you can about it, carefully install it, run it as recommended and expect a long life out of it.
  5. skyash

    skyash Active Member

    I think the easiest motor is the ktm 4bolts put the chain on and your done .and thay seem to go forever i still haven't seen a broken one .and thay do 45mph on a heavy little dirt bike .so a 26inc push bike should get 50mph or more all every day out the box .no no bad cdis opening ports spark plugs nothing there fantastic. Just cost so much
  6. But dont you have to fab custom engine mounts for the ktm 50
  7. skyash

    skyash Active Member

    Thinks it's a direct fit with a cag and thats a fit with a 4 stroke 142f so a 4 stroke mount will work or drill holes in it to match the motor.
  8. Thanks im still a quasi newbee i have basic mechanical skills but another view is ofteb necessary to achieve satisfactory results. This site rocks thanks again here in maine there are no resources for gasbike engineering
  9. Steve Best

    Steve Best Active Member

    I drive a KTM 125 2-stroke on the street and am a true KTM fan, but have to add some cautions about using a KTM engine in a bicycle.
    First is the huge jump in power from 2hp to about 8hp. As fun as it sounds, there is danger in that. Especially for someone new to motorized bicycles. The speed possible increases the likelihood and seriousness of injury, and the likelihood of mechanical failure.

    Second is the reliability myth. All the things that go wrong with China Girl (Happy Time, whatever) engines, will also go wrong with a KTM engine FOR THE SAME REASONS. By the time most people get to a costly KTM engine or motorbike, they have gone through several other 2 stroke bikes and have gained experience along the way. They come to a KTM understanding the importance of quality oil, proper mix, good air filters, jetting, and routine maintenance. This is part of the reason my China Girl has run well for thousands of kilometers, experience has taught be how to look after it. I can assure you if you make beginner mistakes with a KTM engine, it will die.

    This year makes 40 years of 2-stroke experience for me, 40 years since I read Gordon Jennings "2-Stroke Tuner's Guide" and 40 years of 2 stroke motorcycles, snowmobiles and chainsaws and jetskis. I believe these simple China Girl engines are a wonderful place to start and learn from, before you move on to KTM and other more expensive makes.

    This is my my 50hp, 300 lbs KTM powered quad, and my recently departed and sadly missed little red power dog.
    This is the way to get thru mud quickly!
    Look at my boots. This quad can truly "blow the boots off ya!"
    And yet, I still love the simple China Girls.

    Last edited: Sep 11, 2016
  10. How is the reliability of this motor power is good but reliability is paramount
  11. I have no intention of mounting a ktm 50 on a bicycle i was just curious, after 5 builds i have learned that reliability and safety trump last frankenstien build was a ktm 495 in a sears dune cart got tired of buying new underwear and sold it .i do appreciate your concern for safety. Will definately talk to you again , Jerry nason
  12. Steve Best

    Steve Best Active Member

    Ha! Are you asking about the KTM powered quad or a KTM powered bicycle? I can probably answer both.

    The KTM 250 powered Blaster quad is much like any other engine swap project. It is an engineering project totally dependent on your skills and experience. The first trips discover weaknesses and problems that need to be overcome. The more understanding and experience and resources (mainly money!) you have, the better you can solve the problems and build in reliability. It took a year of gradually increasing trips to build reliability into the KTM Blaster. Problem areas were the chain guide, frame cracks, mount loosening, pipe cracks, and lengthening the swingarm to try to keep the front wheels on the ground. I run mud tires because traction on soft stuff is a problem. The close ratio gearbox is a problem, had to settle on a 65mph top speed so I had enough 1st gear to crawl over rocks and logs.

    Reliability of the KTM 50 (or any KTM 2 stroke)?
    KTM uses top quality materials and design in its products, so if you do your part, they will last a long time. Your part is assembling and maintaining the motor properly. Cheap oil, no oil, overheating, detonation, wrong jets, poor air filter or bad pipe tuning will kill a KTM just as it will any other 2 stroke engine, and it will cost more to repair. Any KTM 2 stroke made after the mid-1990s is a wonderfully well made machine. The same could be said of any of the Japanese makes I suppose. The KTM 50 is actually made by another manufacturer, but all of this still applies.

    The China Girl is not made to the same quality standards, but is so simple and unstressed and inexpensive as to be easy to assure some reliability.