Fix your Mini bike Carb - bogging, cutting out etc
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- เผยแพร่เมื่อ 21 ส.ค. 2024
- If you are having trouble with your mini bike/quad whereby its difficult to start, bogging down, cutting out or overflowing then this video could help you get it running sweet.
Of course i would check firstly that there is compression, (the pull start should be difficult to pull slowly) and that there is spark. Do that by removing the spark and with it still connected to the HT lead, Place it against the cylinder and pull the starter. You should get a spark arcing across.
Carbs are pretty much the most common of all problems on these mini 47 and 49 cc engines and that can be anything from overflowing, which is caused when the float gets stuck in the bottom of the bowl or when the cut of valve gets stuck open too, to cutting out and bogging down, This is usually a blockage of the main jet. It is very important to keep the jet clean and to make sure you can see clearly through it as seen in the video. if you get dirt in here then less fuel is able to get through when on open throttle and the bike is starved, causing it to cut out or loose revs.
make sure to get the 2 stroke ratio to fuel right too. A lot of the blockage problems are generally caused by having too much 2 stroke mixed in and it turns gooey after a while.
Thank u brother. Im no mechanic but i bought my daughters a quad for their christmas and it worked for one day. So I've spent at least two weeks learning everything i need to know about these mini quads to make sure i get it working for them! I'm certain my fuel was contaminated. Quad starts and cuts out in less than 10 seconds so its gotta be carb. Replacing inline fuel filter in the morning, and spark plug has already been replaced. So if replacing fuel filter does not work, my next step is cleaning the carb. You have made this easy for me to learn, and may just have saved my ass and handed my daughters a fun day out tomorrow. Much appreciated 🧡
Hey buddy. Thanks a lot. I'm glad to help you out. Hopefully all goes well with it and you get to take it out for some fun! 🙂
@@CptMishMashVonRandom hey mate. Any chance u can give me some advice? I removed the carb and it was clean. The jet however had something in it and i blew it out. I put the carb back together and its still not working mate. I loosened the throttle from the carb by hand and it popped up nicely. However, i could not screw it back in properly. So my questions are:
- Can this affect the quad not starting?
- Is there any specific way to have this screw in properly? It seems like its threaded because any time i try to tighten by hand it just pops off. The pin of the throttle definitely goes into the hole/port inside of it ok, but still can't seem to tighten it on. I never played with it much to actually thread it. It came off easily by hand.
Thanks bud
@@jsmith3966did you figure it out
@@jsmith3966 replace your ignition coil next
Thanks Man, i’m currently working on a 50cc pocket bike, and there is gas overflowing everywhere, this is very simple and helps a lot thanks man
Cheers man. I hope you get it sorted. 👌
Thanks for the tips ,now I can raise hell on my ancient mini Moto in this lockdown
good old covid days
this pretty much fixed all my problems on my 4 year old chinese dirtbike (which is still suprsingly running)
showing my 12 year old daughter this as she needs to know how to take them apart useful info thanks :)
paul rockett Hey, Glad to help. I also had my 9 year old (at the time) strip and rebuild them with me. It's really quite easy to work on and is something you might need to do fairly regularly so definitely worth knowing.
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only if all the chicks dads in school made em do that
only if all the chicks dads in school made em do that
only if all the chicks dads in school made em do that
Thanks Cpt MishMash, this really helped today as I put together a project pocket bike for my kid. Cheers!
+Rusotz Great to hear, mate!
I don't often hear back from those who found it useful so it's good to know it's helping someone get back up and running. Don't forget to drop us a Like & Subscribe! :D
Hi, you need to fully extend the pull cord, then with it all the way out, you rotate the spring loaded disc on the inside of the pullstart mechanism until the spring gets nice and tight. then you allow it to retract the pull cord which is still fully extended at this point. It will rewind the cord and you'll be back in business. :)
Your very welcome mate, glad to help you out. Just make sure the bearing isnt damaged in the bell housing from the chain being too tight. that can also be a cause of the clutch failing so have a look at that before fitting any new parts. :)
This video is brilliant little bike is running sweetly now, only problem I had was getting carb on and off bike.😤 the fixing screws are Phillips and it was hard work getting access. In the future I'll replace them with hexagon head bolts.
Yup, I did exactly that. It's a lot easier to access with hex bolts.
Glad you got it up and running! 👍
Thanks mate, i know it looks scary but its actually pretty easy, I've had my 4 and 9 year olds help out and they know how it goes together. :)
Hi, The fuel tap work by allowing fuel through a small "half circle" shaped channel in the underside of the tap itself. When you turn it off the channel no longer lines up with the inlet and exit for the fuel, so no fuel gets through. Its assembled by first placing the rubber seal into the housing, then the spring washer, then the tap, then flat "U" shaped washer and then finally the retaining plate. You'll feel slight resistance when its fitted correctly. :)
thanks for the info in the video it has helped me get my mini bike starting and running.
Delighted to help, mate. Don't forget to give us a thumbs up! :D
Just purchased a non running mini moto for £35 advertised as a non runner, noticed a few problems with the carb already, ordered a new fuel tap for £2.99 I have spark and compression. Hopefully I'll have ot running by the weekend! Will be a bargain of an investment :)
Hi, You do so by removing the little circlip on it and move it up or down a notch. it can a trial and error affair until you get it on the sweet spot.
However, if the bike used to run perfectly then id be inclined to say that isn't the problem but i dont know whether your bike ever ran better than right now?. If it used to run good then its more likely to be a dirty jet, the long thin brass coloured cylinder that you see being removed from the carb in the video. Hope that helps. :)
Hi, you'll see lots of people have posted the same question. Its likely that the overflow jet is clogged or the float is stuck, it can have sharp edges on it from manufacture and causes the float to get snagged inside the bowl. :)
Its an over flow tube mate, it should hang down and go through the little hole at the bottom of the carb bowl so its free to drain fuel out if the bowl gets overflowed.
The substance on the screw is actually used in order to prevent the screw from coming loose and allowing the idle to get messed up. To remove the carb you first need to take off the filter, then the filter adapter as its covering the bolts that secure the carb to the inlet manifold. Its quite simple really.
Helpful video and good note in description box
Thanks. I'm glad you found it useful. 👍
Yeah it could be indeed. If theres any crap in there, or even if the seal is broken down it can cause an obstruction that prevents the engine from properly fueling on throttle. It can often seem perfectly alright on idle too.
Video was very simple and to the point. nicely done. thank you.
Really glad to help, mate. don't forget to drop me a like & Subscribe! Makes it even easier for others to find the video. :D
Give me a shout if you have any more issues. :)
Exactly the same problem as I had, follow your rev cable down to your engine and pull the full thing out, you can see a needle give it a clean in petrol and it no longer overflows :) Just make sure you push it all the way down when tightening.
Cool! I love finding little gems like this. very satisfying when you get them running. :)
Yes the float level is exactly what affects the drip from the over flow. It can happen for a couple of reasons.
1. the valve that the float is opening and closing isnt sealing properly when closed.
2.The float is getting stuck and isnt able to close the valve as it should.
take the float out and inspect it for any rough edges, also check the valve its operating to make sure there nothing blocking it, and finally check the arm that the float is moving to open and close the valve. :)
Turn the idle screw clockwise to screw it in and to lift the revs. turn it loads and see if it gets better. once ya get it to run reliably then you can gradually roll it back to get it sitting and a lower steady idle. regarding the cable, its not the cable you adjust, its the carb shuttle, the cylinder that moves up and down as you turn the throttle cable. theres a needle through the centre of this and by adjusting the position of the needle, the mixture is adjusted. :)
The coil is the cable part that attaches to the spark plug. The pickup is the end of that coil where it meets the flywheel.
It can do, yep. there's nothing as good as a complete strip down and clean, but at the very least, remove the main jet and give that a clean out. Spray some carb cleaner into the base of the carb and down the port too and hopefully that should help you out.
thanks my 80cc motorized bike kit build was bogging down then dying so i just opened the carb cleaned it all then this video helped me identify some problems for one there was some rubberlike tiny chunk in my mainjet and my float was faced the wrong way havent tried giving it a go scince correcting theses but im feeling very optimistic thanks
If you are not getting spark and you know its a good plug then you probably need a new coil. This is the wire piece that connects onto the spark plug. It might just need to be adjusted though. take off the pull start cover and have a look at the coil to see if its sitting nicely against the flywheel. you can adjust them to get a better magnetic connection. it'll be much clearer when you look at it. :)
make sure the plug is the same type as the one that came with the bike. you can check the spark by removing the plug and plugging the coil back onto it. pull start the bike while touching the end of the plug off the metal of the engine. you'll see the spark jumping. do not touch the metal though, hold it by the rubber.
I would definitely clean the carb though, if the bike is that old then its probably gonna have loads of dirt in there. give it a good cleaning and it should run like clockwork. :)
If its cutting out, try bending the arms ever so slightly upwards towards the top of the carb and that will allow the bowl to fill to a higher level. There's also the possibility that the float may just have some rough edges on it and is catching on the inside of the bowl. This is quite common and has the same symptoms you are having.
First, you make sure there are no sharp edges that are causing it to get stuck. if there are, smooth them with sandpaper.
Then you check the valve is opening and closing properly and is clean. That's the tiny little piece with a point on it that gets pushed in and out by the brass lever arm.
If both of those are ok then your problem is due to the brass arm itself. Its probably miss shaped and needs a little adjustment so the float actually lifts it enough to cut off the fuel. :)
carb cleaner is fine to use yup, Your problem could be one of 2 common issues,
1. the carb bowl cant fill fast enough to deliver fuel fast enough to the engine. This is usually an issue with the fuel tap, cut off valve or the float.
2. The throttle pin can cause the same problems as it regulates the ratio of fuel to air. you can correct it by removing the circlip and moving it up or down a notch and see if it helps. :)
I know the one your talking about, check the fuel tap and the cut off valve in the carb, the bit that the float opens and closes when the bowl fills up. :)
Just start by giving the carb a good cleaning and make sure the jets are free of dirt. then when reassembling it, make sure you tighten it down enough to give a good air seal between the carb and the inlet. If you are still having problems at that point then I would adjust the mixture needle on the end of the throttle cable in slight increments until you get it at its sweet spot. Also, make sure the idle screw isn't turned down too low. Hope that helps and if you need any more info, shout. :)
Pull the fuel line where it goes into the fuel tap and see if it will flow freely from there. If it does then you'll know the tap is the problem. If it doesn't then its either the filter or even dirt in the line from the tank. The taps are common causes of these problems when the rubber seal inside them gets torn or unseated. You can strip the tap to inspect the seal quite easily.
I'd hazard a guess that your float is stuck in the bottom position and not cutting off the fuel. Try opening the tap and lightly tap the bottom of the carb to see if it will stop flowing. Ideally I would take the bowl off and give it a clean and make sure there are no sharp edges or anything on the float that would cause it to snag. Check the cut off valve is clean and clear too. :)
It depends on your bike really, but screw it in until you can get the bike to stay running without revving it. then when its warm, back it off little at a time if the idle speed is too high.
Hi, it may be seized. try removing the spark plug and turning it again. also, drop some oil down through the spark plug hole to lube the cylinder. hopefully it'll turn over then.:)
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If its been left sitting then I would be almost certain that the carb is gunked up with the fuel/2stroke mixture. It starts to separate and block up the carb with a mayo'like gunk. This is why it is good practice to turn off the fuel tap before cutting the engine off. It wastes up the surplus fuel in the carb so its not left to go bad and gunk up the carb. :)
If your carb is still not working after you follow ANY of these fix it videos then bypass the petcock (on/off switch) by taking the guts out and sealing the opening with a faucet washer, a homemade gasket and silicone. Your new gas shut off will be a 3/8 bolt. It's pretty easy to figure out when you take it apart and see all the debris and broken parts that this is why NO gas is getting to your carb. Check it out. You'll agree.
Thanks! Short and directly to the point. Way to put the YOU back in to TH-cam...
@HBomb101273 Hi, Thats happening because your float is stuck and isnt cutting off the fuel supply when the carb is full. Its the part at 3:30 in the video, a white plastic ring float. check that out and make sure the bowl is clean.
@MrsBatmansMom you shouldnt need to adjust the forks, not unless they have been bent or something. its either going to be the cut off valve, which is the little needle like pin that attaches to the fork or it'll be the float which sometimes can have sharp bits of plastic around the edges that catch on the sides of the carb bowl. make sure to fit the float the right way around too. :)
If its always been like that then its possible its just case of the carb needle needing adjusting. Its probably running too rich or too lean on its current setting. I'd clean the carb first and see if that helps. If not then try different settings on the carb needle and that should have you running again. :)
lol, yup, its simple to put back on. you just insert it as it was when you removed it. you should be able to remove it by hand but sometimes they are a little tight and you'll need a tool.
yeah thats no problem. I like yo clean them in a small pan of petrol with an old tooth brush and some wire for the tight areas, cleaning the jets etc.
Yeah try cleaning the carb first of all mate, and then if its still the same then you can try adjusting the mixture by moving the circlip up or down 1 position on the needle. If its ever run smoothly before then its unlikely you'll need to adjust the mixture though.
The float levels does sound like a good start but it might also be a restriction in the jet's that's allowing little fuel through on lower rpm. this of course isn't a problem at higher rpm since their is more vacuum. I'd try that and check out the float levels and see if it helps. Generally, when I have problems with these carbs I start by doing a thorough clean in. Finding the problem after that is a lot easier.
Your main jet is probably clogged, or you could have a fuel blockage that is limiting the flow to the bowl. I'd start by removing the bowl and making sure the main jet is clean (thats the gold part that I am looking through in the video). Then when thats clean, test the flow of fuel by turning on the tap while the bowl is still off the carb. It should start to flow out steadily, but if it doesnt then you could have a blockage in the filter, the tap or in the valve inside the carb.
@sniperpr0100 Theres a screw in the bottom of the carb bowl there with a red washer on it. Remove it and the fuel will al drain out. stick in proper fuel and drop a little bit of fresh fuel into the cylinder through the spark plug hole. then try start it again and it should be fine.
your videos are so helpful please make more!
Hey, Thanks a lot mate. I'm really glad you find them helpful. :)
@@CptMishMashVonRandom why haven't you made more? did you get rid of your 49cc ???
You can clean it with petrol or WD40, an old tooth brush and some wire. I use the wire for clearing stubborn dirt from inside the jets. :)
Thank you. Nice work. Is the vent tube supposed to be facing downward?
Yep, that way overflow fuel drip down and away from danger. If it's pointed up then the carb can flood.
Hi, there's a little rubber seal inside the taps and they can tear from age and cause this leaking. You can buy the little rubber piece or just replace the entire tap for as little money. :)
i have a small quad that has the same carb and i cleaned it well replaced gas lines aswell as fuel filter and when i start it it will run but lile 3min later it will die out and turn off. sometimes it will still start sometimes it wont. Thanks for ur time :) (BTW GR8 VIDEO)
thanks man, I don't know a lot about bikes but this helped a lot!
Cool!, Glad to help mate!
I'd really appreciate a like and share if you find it useful. :)
What really the the problem about my quadbike 150cc ?... easy to start and can go as normal, but when it is in high trottle the engine lost power instead of getting more power for a maximum pull, what
@23cross I cant post links here, but just search "minimoto carb", "cag carb", "47cc carb" etc and you should have no problem finding one. they are pretty cheap too but id advise stripping and cleaning it as shown in the video before fitting it. they are usually pretty dirty straight out of the box.
It'll leak a small amount. before you remove the carb, undo the fuel line to it and plug it with a bolt, or keep it pinched if you have a locking pliers.
Once you have the fuel line off, the only fuel that can leak is the little bit thats left in the bowl. :)
Hey, Sounds like your float is sticking mate. its the white plastic part in the video. Take it out and see if theres any dirt in there or even sharp edges on the float itself. Might aswell give the carb a clean while your opening it too though. :)
@23cross remove your spark plug and drop some 2 stroke down the hole, leave it a few mins and then try kick it without the spark plug. it'll probably be a bit stubborn at first but it'll turn over and then just stick the plug back in and see if it'll start. :)
I know it isn't the same carb but hopefully you can help. I recently bought a motor bike kit and it came with a "new" CNS EPA carb yet the instructions/owners guide only deals with an older model without a choke etc. This is my first time to every construct or deal with a project with a motor, etc but did manage to get it all working and running nicely. The only problem is that a tube apparently called the overflow valve is leaking slowly when I ride. I have been reading tons of forums to better
it could be burrs on the float that's causing it to get stuck mate. you'd be surprised how dirty they can be from the factory too. :)
@suckdsniggamw2rocks Firstly, check if the bike has a choke and they is isn't set to ON,
If that doesn't help ya, try adjusting the position of the needle on the carb shuttle. Making it longer will allow more air to the fuel mixture, making it shorter will allow less air to the mixture. It just depends on what setting its currently on.
Check out the friction material on the clutch itself and see if its worn out, its underneath that clutch bell and will have 3 mating surfaces.
Just take the bottom of it off (the carb bowl) and clean the float in there and make sure its not binding. You'll see the little valve in there that is controlled by the float, clean that too. :)
I don't think it will be available seperately to be honest. its just a generic screw though, you could get one from a hardware shop and fit a little seal to it.
@TheMiguel0205 It sounds like it could be seized. take off the spark plug and see if it'll pull then. you can drop some 2 stroke oil down through the spark plug hole to make things a little easier. You should also remove the pull start and make sure nothing is stuck in there thats preventing you from pulling it. :)
You need to fit the rubber into the tap, then fit the circular metal piece that you discribed, then the plastic tap and finally the horse shoe shaped piece to secure it all down.
Ebay is your best friend when it comes to minimoto parts mate. it'll be pretty cheap too. :)
@zHardcoreCinema lol, you dont have to open everything, just unscrew the cap and pull out the rev cable from the carb. The needle is on the end of it and the washer i was referring to is a sort of retaining circlip that holds the needle in its position. Theres a 4-5 different poistions you can set it to. you'll understand as soon as ya see it. :)
Your float isnt cutting off the fuel. Take off the bowl and check the float for any debris, also check the valve here the fuel it coming into the bowl. :)
Try it with the choke off and adjust the idle screw in a little bit until it can run be itself. let it warm up and then just fine tune the screw so that you get the idle nice and low, but not low enough to cut out. :)
yeah you can do that. its handy to use a piece of wire to get into all the tight spots and channels too though.
@stanMADD97 Hi,
Sounds like your float is sticking or your cut off valve which is connected to the float could be durty or blocked. This prevents the float from being able to shut off the fuel when the bowl is full. It can also be the cut off levers arm which is the brass coloured C shaped piece made from thin metal. if its shaped incorrectly then it'll sometimes prevent the cut off from operating. compare yours to the one in the video. :)
That's what I would start with, yes. If that doesn't sort it then it will make finding the problem easier anyway.
Start by cleaning and inspecting all the parts, then reassemble as shown in the video. If it still happens then try adjusting the mixture in slight increments by moving the circlip up or down and testing again. :)
Just screw the idle screw in enough for the bike to run and then adjust it when warm to idle nicely without cutting out. its pretty simple really. :)
Its only in very rare circumstances that you'd need a new carb mate, almost always its just in need of a cleaning/adjusting. :)
Jennifer Winterbauer Yes That would be most likely. More often than not it'll be down to dirt in the main jet. :) don't forget to like and subscribe. :)
Yeah don't worry about the threads on the idle screw. its fine.
Hi, have you adjusted the idle screw to keep the revs up on idle? if not, give that a go and see how it performs then. If thats not it then its likely to be the mixture so you have to adjust the needle in the throttle cable. There's info on doing that here in the comments from previous questions but give the idle screw a go first and let me know how you get on. :)
Has it ever ran smoothly or has it just started doing it? It could be a fuel blockage in either the tab, the inlet valve or the main jet that isn't letting enough fuel through and is letting the engine bog down. Start by giving the carb a good clean and see how it performs from there. :)
If it has compression and doesnt fire when you drop fuel down through the spark plug socket then you have an ignition problem. Either a bad spark plug, a bad coil or the pickup isnt adjusted correctly. It is possible for it to have a spark but not a strong enough one to ignite reliably. Check those out and let me know how you get on. :)
@suckdsniggamw2rocks Yeah if you are not confident in getting it right then maybe you could just take it in. It might even be easier to bring them the carb and ask them to clean and rebuild it for you. This of course would require some setting up when reinstalling to the bike so you'd have to consider that. In the meantime, check for fuel flow blockages to the carb bowl, check for area's on the float that might cause it to get stuck etc etc.
I woulda loved to see the video of what your bike was doing to make one think it's a carb issue.
Difficulty starting or bogging down when throttling are common indications.
Oh right, didn't realise it was ridge side down for the float, thanks!
@666TECHNO666 Defo dont do that, the crank nut can sheer off and ruin the engine. you'd need to get a new crank and rebuild the whole thing. :)
Try dropping fuel through the spark plug hole and see if it fires then. it should start easily then. If it doesn't then the next thing you would test you are getting spark. Do this by removing the spark plug, connect it to the coil and crank the bike while touching the spark plug off the engine. you'll see it spark if its working.
Hi, If its overflowing then there is a problem with either the float or the valve it operates. I'd start by giving it a good cleaning and then see if it'll run better. If not, it could need float height adjusted.
That sounds like your clutch is sticking. Is the chain too tight maybe? Remove the chain and see if you stick get that catchy feeling when pull starting it. You can remove the clutch bell aswell and see if anything stands out. Its only 4 bolts and nothing will jump out at you. :)
White spirit will be fine, yup. You can also use clean petrol, carb cleaner spray etc.
@zHardcoreCinema Have you tried adjusting the position of the carb needle? its on the end of the rev cable that you will have inserted. pull out the rev cable and have a look at the needle on the end. you can remove it from the carb slide and move its retaining washer up or down, depending on where its located at the moment. :)
@OX805NARD You either dont have enough power in the battery or the starter is seized or need a new starter relay. you'll need to check them out to know for sure.
Check it to see if fuel is able to pass through it freely. If its clogged then you'll have to replace it.
I don't imagine both problems are related. The chain might be too tight, causing it to bind up when you roll it. Try moving the wheel slightly forward. As far as the idling goes. are you running 2stroke in the fuel? if so, what mixture? Have you ever cleaned the carb?
The throttle cable just unscrews from the top of the carb. Stripping and rebuilding the carb is pretty easy. everything you need to know is in the video. :)
Also you may have some dirt inside your jet needle pull that out and give it a clean in petrol.
@sniperpr0100 Did the cut off button get stuck maybe?
Try dropping a little bit of fuel down into the spart plug hole. If it fires then you'll know your car isnt fueling properly, if it doesnt you'll know your not getting spark.
I would say the best thing to do is to clean the carb thoroughly first of all, If it persists after that then I would be looking at adjusting the mixture needle a little. Let me know how you get on, or if you need a better explanation. :)
@23cross Why do you need another carb? just strip and clean the one you have as shown in the video.
If you buy a new one there's a good chance you'll have to clean that anyway. Sometimes they can be filthy from manufacturing straight out of the box.
Your welcome mate, Glad you got it going again. :D