I bought a bike off a guy for my son's 15th birthday last week and he hasn't got to ride it for a total of an hour. It kept quitting on him, now won't run at all. He's so disappointed and I can't find anyone to look at it. The guy I bought it from is 100 miles away and ignoring me anyway but my husband has looked at it a little but doesn't know what to do with it, he said he thinks it's a problem with the carburetor.... I'm wondering if there's anyone in my area that knows how to work on these? I'm in Southern Indiana, close to Louisville.
frustrated mom
- Thread starter dsebastian
- Start date
Welcome to the forum. We might have a member that's near enough to offer some assistance but until we determine that let me assure you we'll do everything we can to get your boy on the road.
We have an extensive knowledge base here most of which can be had by using our 'search' feature. Members are also usually here and willing to offer assistance. However we need some specifics before offering help. Can you tell us a little about the engine? Is it a Chinese 2 stroke engine? I realize that you might not have the answer handy but if you can find out for us we can begin to offer some troubleshooting ideas.
In the event that the engine is the typical, and very common 2 stroke, here is a quick guide to help pinpoint where the problem might be > http://motorbicycling.com/showthread.php?t=35090
Hopefully this will help but stay tuned for more input from our members.
Tom
We have an extensive knowledge base here most of which can be had by using our 'search' feature. Members are also usually here and willing to offer assistance. However we need some specifics before offering help. Can you tell us a little about the engine? Is it a Chinese 2 stroke engine? I realize that you might not have the answer handy but if you can find out for us we can begin to offer some troubleshooting ideas.
In the event that the engine is the typical, and very common 2 stroke, here is a quick guide to help pinpoint where the problem might be > http://motorbicycling.com/showthread.php?t=35090
Hopefully this will help but stay tuned for more input from our members.
Tom
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Welcome to the forum, youre in the right place if you need help getting back on the road, there's a lot of talented and helpful members in here.
Pics always help, and describe in as much detail as possible, we can help and I'm sure there are members in your area that may be willing to take a look at it... if not, just post pics and give as much detail as possible and one of us can walk you thru what to check for and possible fixes. These things are crazy simple and a set of basic tools is usually all that's needed to get back on the road.
Pics always help, and describe in as much detail as possible, we can help and I'm sure there are members in your area that may be willing to take a look at it... if not, just post pics and give as much detail as possible and one of us can walk you thru what to check for and possible fixes. These things are crazy simple and a set of basic tools is usually all that's needed to get back on the road.
Yup! Bikes of this sort tend to frustrate newbies. But then there comes a day when you 'get it'. And they're very loveable after that.
Have your son come to this site and start reading. Any headline that looks interesting. In no time at all he'll start seeing info that pertains to his particular bike. Like one of the guys above stated, very basic tools will get him through it.
He'll find himself understanding and fixing his own bike.
And then he'll be off and running.
Have your son come to this site and start reading. Any headline that looks interesting. In no time at all he'll start seeing info that pertains to his particular bike. Like one of the guys above stated, very basic tools will get him through it.
He'll find himself understanding and fixing his own bike.
And then he'll be off and running.
I agree with this. Motorized bicycles are actually modified bicycles and so they require more maintenance and tinkering than other forms of transportation. Your son needs to be able to learn how everything works and how to fix problems as a hobbyist would, not just be able to ride it. It's a great education into basic mechanics for a beginner but he has to have the interest in learning about it. He will find all the info he needs at this website and people to answer questions too.
Thanks everybody, I really appreciate the info, it's a 2 cycle kit from china and I will post pics when I get back home.
Thanks for getting back to us.
Fuel to oil ratio is a much debated issue here. Typically the kit instructions will advise a ratio of 16:1. That means 16 parts gasoline to 1 part oil. It has been determined by a number of us that the 16:1 figure is a little high on oil content and we generally suggest dropping the ratio to about 24:1.
You'll also hear 32:1 and 40:1. There has never been a real consensus on what it best so you might want to do some reading and see what appeals to you. Use our 'search' feature and type in 'oil ratio' or 'oil' and you'll have lots to consider.
With that said you can't go wrong with the 24:1 mix ratio. Use 2 cycle oil, preferably one that is formulated for air cooled engines and you'll be safe.
You'll also get several more replys to this so check back soon.
Tom
Fuel to oil ratio is a much debated issue here. Typically the kit instructions will advise a ratio of 16:1. That means 16 parts gasoline to 1 part oil. It has been determined by a number of us that the 16:1 figure is a little high on oil content and we generally suggest dropping the ratio to about 24:1.
You'll also hear 32:1 and 40:1. There has never been a real consensus on what it best so you might want to do some reading and see what appeals to you. Use our 'search' feature and type in 'oil ratio' or 'oil' and you'll have lots to consider.
With that said you can't go wrong with the 24:1 mix ratio. Use 2 cycle oil, preferably one that is formulated for air cooled engines and you'll be safe.
You'll also get several more replys to this so check back soon.
Tom
I'm sorry the thing quit on him, they can be cantankerous before they're dialed in. You will need a few tools to keep a china girl running.
I agree with Tom on the oil ratio, 24/1 is nice protection for that new engine.
The cylinder head is held on by 4 nuts, I'd check that right off the bat, if it's loose enough it will quit running. Barring that, your husband is probably on the right track but I would start from the beginning and take the gas line loose from the carb and feed it into a tincan, and open the valve. If there is a small, steady trickle of gas- so far so good.
Put it back on the carb, turn it on, press and hold that little brass button (primer or tickler) for a few seconds to flood a little gas into the carb throat, pull the choke lever up (on) and try a start.
Next take out the spark plug and see if it has seen any gas, with the choke and the tickling, after 25 yards of hard peddling it should be getting wet. If so you are probably ok for now in the carb department. If not, take off the carb and go watch the you tubes about NT carbs, they are so simple you will be able to check, clean and reassemble it by following those videos.
If the plug was wet and no start at all you probably have a spark problem, and the info to fix that is here, too.
The bikes really are fun, but they take a little effort to get them running strong and reliably.
I haven't had to fix anything or had any trouble with mine in months. They can be decent little engines once you get em going.
Good luck to you!
I agree with Tom on the oil ratio, 24/1 is nice protection for that new engine.
The cylinder head is held on by 4 nuts, I'd check that right off the bat, if it's loose enough it will quit running. Barring that, your husband is probably on the right track but I would start from the beginning and take the gas line loose from the carb and feed it into a tincan, and open the valve. If there is a small, steady trickle of gas- so far so good.
Put it back on the carb, turn it on, press and hold that little brass button (primer or tickler) for a few seconds to flood a little gas into the carb throat, pull the choke lever up (on) and try a start.
Next take out the spark plug and see if it has seen any gas, with the choke and the tickling, after 25 yards of hard peddling it should be getting wet. If so you are probably ok for now in the carb department. If not, take off the carb and go watch the you tubes about NT carbs, they are so simple you will be able to check, clean and reassemble it by following those videos.
If the plug was wet and no start at all you probably have a spark problem, and the info to fix that is here, too.
The bikes really are fun, but they take a little effort to get them running strong and reliably.
I haven't had to fix anything or had any trouble with mine in months. They can be decent little engines once you get em going.
Good luck to you!
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Hello frustrated mom ....
Spfld. Illinois here.
I bet the great advise here will get you going again!
Post a few photos, ask questions, visit often, and I bet your son will have air in his face soon!
Spfld. Illinois here.
I bet the great advise here will get you going again!
Post a few photos, ask questions, visit often, and I bet your son will have air in his face soon!
Honestly.. sell the motorized bike and just get a road bicycle.. a 15yr old on a new aluminum framed road bike with high pressure tires will be rolling as fast as most people here (25mph).. A motorized bike will up that to 30-35mph.. you decide if you want your 15yo going that fast.. If there isn't a highly hands-on mechanical-mind type person in the family that is willing to learn about and fix ALL of the problems with these bikes, then you're pretty much entering a world of pain. The engine is just the beginning, wait till you get problems with wheels, bearings, chain, throttle cable, brakes, tires, etc. Not to mention anytime you have a bicycle-related problem, NO shop will work on it because of liability issues, so you'll have to remove the engine kit parts every time for them to work on it.
To ride one of these you have to really want to learn and conquer the very steep learning curve in identifying, correctly diagnosing, and fixing problems. Unless your son is very interested in working on his bike and how stuff works.. I would sell it and either get a road bicycle or a moped.. at least you get a warranty and numerous local mechanics for each.
To ride one of these you have to really want to learn and conquer the very steep learning curve in identifying, correctly diagnosing, and fixing problems. Unless your son is very interested in working on his bike and how stuff works.. I would sell it and either get a road bicycle or a moped.. at least you get a warranty and numerous local mechanics for each.
Thanks so much for the replies everyone, I've been showing them to my husband and he is working on it when he has extra time. I'm not sure about my son working on it, I think it would be good for him to know about these things but he doesn't have a clue. Hopefully with my husbands help he can learn along the way.
Welcome!
15 years? He's plenty old enough. Crash and burn on a 30 mph bicycle or a 60+ mph dirtbike? I think she made a solid choice.
Anyway, let's learn the basics of troubleshooting:
Fuel, air, compression, spark. If you have those, it should run (or try to run). Get them in the right proportions and it should run well.
Fuel: the carburetor controls that. There's usually an inlet valve that you can use to shut fuel off to it. There's a choke lever for cold starts (up is choke, down is for after it starts). There's a button on the left side for getting the fuel to flow in to the carb. I've never needed to use this. Ever. Carburetors don't just stop working suddenly unless something came off of it. I doubt this is the issue.
Air: there's an air filter. It's behind the "punisher" looking black plastic piece. If there's a plastic bag wrapped around the punisher, then it won't run. Otherwise, you probably have air flowing in. Getting air out is important too. If the exhaust got clogged, it could stop running. Ever heard of people putting potatoes in tail pipes? So the air part is probably not likely.
Compression: So the piston goes down, air and fuel go in. The piston goes up, and it compresses the air/fuel mix. Having compression in the engine is important. As was stated earlier, the compression can be lost (without warning) if the 4 nuts on top of the engine come loose. Tighten those bad boys down. Not too much, and do it evenly. If you crank them down too tight they can snap. You can tell if you have compression by riding the bike with the clutch lever pulled, then release the lever. Does it get hard to pedal? Hear a pop pop pop pop? That's compression!
Spark: This is where my money is. You need it to spark to work. When the piston comes up and squishes the air/fuel mix, the spark plug should fire at (or close to) the top. Then everything explodes and makes power! The piston goes down and the cycle repeats. So there's a magnet spinning on the right side of the engine. As it spins past a coil of wire, a little electrical signal is made (called induction) in the coil. That signal goes to a black box called the CDI. The CDI is where the magic happens. It stores electrical energy and fires a whole bunch all at once when the time is just right. Most times when the bike just suddenly quits, either the coil or the CDI is to blame. You can test spark pretty easily. Take the spark plug out, and put the wire on the spark plug again (so now you have a spark plug dangling by the wire) lay the spark plug's metal end on the engine (metal to metal contact is a must). Pick up the rear tire and pedal with the clutch lever released so the engine spins. See sparks? Good!
So there you go. Troubleshooting basics. Fuel, air, spark, compression. That's it. Now you know enough to fix it every time!
15 years? He's plenty old enough. Crash and burn on a 30 mph bicycle or a 60+ mph dirtbike? I think she made a solid choice.
Anyway, let's learn the basics of troubleshooting:
Fuel, air, compression, spark. If you have those, it should run (or try to run). Get them in the right proportions and it should run well.
Fuel: the carburetor controls that. There's usually an inlet valve that you can use to shut fuel off to it. There's a choke lever for cold starts (up is choke, down is for after it starts). There's a button on the left side for getting the fuel to flow in to the carb. I've never needed to use this. Ever. Carburetors don't just stop working suddenly unless something came off of it. I doubt this is the issue.
Air: there's an air filter. It's behind the "punisher" looking black plastic piece. If there's a plastic bag wrapped around the punisher, then it won't run. Otherwise, you probably have air flowing in. Getting air out is important too. If the exhaust got clogged, it could stop running. Ever heard of people putting potatoes in tail pipes? So the air part is probably not likely.
Compression: So the piston goes down, air and fuel go in. The piston goes up, and it compresses the air/fuel mix. Having compression in the engine is important. As was stated earlier, the compression can be lost (without warning) if the 4 nuts on top of the engine come loose. Tighten those bad boys down. Not too much, and do it evenly. If you crank them down too tight they can snap. You can tell if you have compression by riding the bike with the clutch lever pulled, then release the lever. Does it get hard to pedal? Hear a pop pop pop pop? That's compression!
Spark: This is where my money is. You need it to spark to work. When the piston comes up and squishes the air/fuel mix, the spark plug should fire at (or close to) the top. Then everything explodes and makes power! The piston goes down and the cycle repeats. So there's a magnet spinning on the right side of the engine. As it spins past a coil of wire, a little electrical signal is made (called induction) in the coil. That signal goes to a black box called the CDI. The CDI is where the magic happens. It stores electrical energy and fires a whole bunch all at once when the time is just right. Most times when the bike just suddenly quits, either the coil or the CDI is to blame. You can test spark pretty easily. Take the spark plug out, and put the wire on the spark plug again (so now you have a spark plug dangling by the wire) lay the spark plug's metal end on the engine (metal to metal contact is a must). Pick up the rear tire and pedal with the clutch lever released so the engine spins. See sparks? Good!
So there you go. Troubleshooting basics. Fuel, air, spark, compression. That's it. Now you know enough to fix it every time!
I agree, 15yrs old is old enough...I've been talking to another member on this website who is only 14 yrs old, he's doing great!
in my opinion schools should buy these Chinese two strokes to teach small engine repair basics with. they are perfect learning tools.
you've done good by getting one of these for your kid. encourage him to be involved with the repair, even letting him loose on this forum is probably a good idea, he stands only to learn research skills, if not engine repair.
not to mention the "learning to learn" aspect of having a hobby like this (relatively affordable, and a well tread path before you with lots of advice waiting)
the look on your kids face when the bikes rough bits start to smooth out will be worth it.
you've done good by getting one of these for your kid. encourage him to be involved with the repair, even letting him loose on this forum is probably a good idea, he stands only to learn research skills, if not engine repair.
not to mention the "learning to learn" aspect of having a hobby like this (relatively affordable, and a well tread path before you with lots of advice waiting)
the look on your kids face when the bikes rough bits start to smooth out will be worth it.
