Top 5 Most Common Carburetor Problems & How To Fix Them

[@kcomst]

Great video that covers all the common issues. I've been working on carbs for the past 50 years and only in the last 5 (because of the wealth of info on the Internet) have I finally understood how they work. Prior to that, no matter what the issue I bought a rebuild kit and completely cleaned and rebuilt the carb, a waste of time when 9 times out of 10 it's just the pilot jet is clogged. Love the point he made on jetting, which often gets blamed by people who don't understand. That is another whole topic that could take twice as long. One thing I would add for proper fuel delivery is to make sure your air cleaner is not dirty.

[@rmatvmc]

Good stuff! Thanks for checking out the video and adding your input.

[@OogleTheGreat]

Use non-ethanol gasoline and most of these issues will disappear. I had these problems multiple times, and once I switched to non-ethanol gas, they stopped. Not a single issue in the last 5 years. I know, the Owner's Manual says that up to 10% ethanol fuel is OK to use. It is really up to you. You can save money on the type of gas, and spend your time removing-cleaning-reinstalling the carburetor on a regular basis. Or spend a few dollars more and spend your time riding. And "No", 93 octane does not fix the problem. The jets in these carburetors are small and gum-up quite easily with the ethanol gas. It took me about 5 carburetor cleanings to discover this issue. I prefer to spend an extra $1/gal for non-ethanol fuel instead of spending my time wrenching on the machine.

[@ME-wq8lq]

Is it ok to leave non ethanol fuel in the tank for long periods of time?

[@OogleTheGreat]

@@ME-wq8lq Define "long period of time." I would not leave any type of fuel in the tank longer than 6 months. If I plan on leaving gas in the tank for more than 2 months, I always add a stabilizer. My favorite is Startron. I have used Startron in my outboard, chainsaw, motorcycle, tractor, weed-eater, generator, and my Ram 1500.

[@ToridoodlesAnderson]

Hi

[@hid3nax]

Lucky you if you are able to source non-ethanol fuel somewhere near you. In EU, all fuel contains ethanol, unfortunately

[@cody-gaming7593]

I actually recently switched to non ethanol

[@spartan0722]

Charles, you are the man. I am going to learn how to be a master mechanic just by watching you perform your magic on the big screen, (my 27" computer monitor).

[@rmatvmc]

You are the man! Thanks for watching.

[@jtpimm4603]

One more common thing to add... If you have a brass float with solder joints, check to make sure the floats aren't filled with fuel. If the floats have even the smallest pin hole, they will fill with fuel and sink, opening the needle valve, causing carb overflow.

[@bobbyblenio4571]

Good Call ! I Never thought of That !

[@naderhd3824]

I had that. Thaught I was insane for a Moment. 2 rebuilds and it still leaked. Just a bad float😅

[@ode4492]

Any chance you could make an advanced, “part 2” video? The problem many of us have is not being able to understand a rich or lean condition by sound and with the bike running through its throttle range. For instance, I commonly mistake a too-rich condition as being lean and end up jetting the wrong direction and make it more rich. There’s simply not a lot of GOOD videos that cover this real well. I feel like you guys could nail it.

[@rmatvmc]

You make some good points. No promise, but we might do a jetting video with those examples. I have a few examples recorded on a two stroke and once you know the sounds, it's hard not to notice them. Stay tuned!! -Charles

[@scottyboy7462]

yup- every carb issue ive had was in that top 5. excellent vid bro!

[@rmatvmc]

Thanks! 👍

[@richardchang9740]

I swear Rocky Mountain knows what my probs are, have a klx250 , rough idle, checked everything, now have to check spark plugs... thx thx

[@rmatvmc]

You're welcome! We're here for you ✊

[@sleepyrasta420]

4:55 I've had that problem before with the fuel seal at the bowl i microwaved it for 15 seconds and it went back into shape but you need to open a window for the smell and keep an eye on it while it's in there

[@colindoyle6149]

WELL!!!!!!!! Thank you so much for this video! I've been hunting videos on bogging issues with my CRF450X supermoto before i pulled the carb..... thinking E10 fuel ate up the rubbers (not ruling it out just yet) but going step by step i figured out thanks to you I've a shitty flow coming from my tank! so fingers crossed its not the dreaded... bike strip down, carb out and rebuild!! even all local bike garages refused to take it in as they're so busy and its so time consuming so would have cost a fortune!! all happened for good reason i guess! thanks again!! I've liked and subscribed 👍

[@rmatvmc]

Glad you got it figured out and saved some money over taking it to a shop. Thanks for checking out the video!

[@tru3sk1ll]

90% of all carb problems are caused by storing your carb "wet", always store it dry, even for a week, especially in CA with that SSSSSHITTY ethanol infused gas - turn the fuel petcock to 'off' - let the engine idle until it dies (burning out all fuel from carb) - you can also use a screwdriver to drain the bowl, whatever 'floats' your boat - buy a simple siphon pump and drain EVERY BIT OF GAS OUT of the fuel tank 99.9999% of carb problems can be avoided this way, I don't trust fuel stabilizers, and I don't trust anyone's gas supply, and you shouldn't either

[@markdeeframpton]

After draining I give the throttle a few good whacks to get the injector pump empty. ;-)

[@cbob1]

Very good video but would be nice to see the KTM-Mikuni jet block issue addressed.

[@simransingh6170]

Great content mate. I have one question if anyone can answer. I recently bought a 1984 Honda CB 750 Nighthawk. I rebuild the carburetors, and I was able to start the bike. But out of the four 2 carbs are pissing gas towards air filter. what could be wrong ?

[@rmatvmc]

You may have a float that is not sitting correctly. Possibly a needle not sitting properly.

[@bryan_trades8867]

Good informative video , i recently just pulled my carb for cleaning just took off the bottom bowl and cleaned out the main jet now when i start it up it revvs almost full throttle any ideas what it could be? Throttle seems to be good and not stuck

[@rmatvmc]

What machine? Could the cable be caught on something from turning the carb sideways? Sometimes if the cable was pulled tight, the housing can get pulled above the adjuster on top of the cap. FCR Carbs have that O-ring on the slide that can swell if it get's cleaner on it, (if you didn't remove the jet to spray it). Other than that, you might just need to go back through and check your work. -Charles

[@bryan_trades8867]

@@rmatvmcthanks for the reply! It is a 2001 honda 400ex

[@bryan_trades8867]

@@rmatvmc i couldnt fully remove the throttle cable since one of the cover screws was strippped so i just left it on while i worked on the carb could that have caused an issue? And it looks like the last owner removed the idle screw adjuster just ordered one. But the bike was running perfect right before i took off the bowl to check if my float was stuck since it was leaking a lot of gas from the overflow hose. I also took off the main jet to make sure it was clean

[@morenicalv2658]

@@bryan_trades8867hi mate same thing happening with mine did u find a fix?

[@cosmin.06]

I ride a street bike and could really use your help. When I'm crossing in 5th or 6th my bike doesn't like me to use a small amount of throttle. It feels like it what's to die. When in not hot and i I accelerate it to much to quickly it what's to die. Pls help if you can. Ty y'all ❤❤

[@gotdoegotdam9184]

Hope u see this got a 2021 yfz 50 starts and runs at half throttle wide open it boggs and cuts off some fuel in the airbox what could it be???

[@jeremyterry7838]

300 honda fourtrax, i have cleaned carb again and again and i have cleaned rebuilt many for myself and friends through the year with never any trouble. Well this one will fill up with fuel along with the inline filter but the carb bowl will run out of fuel and not fill the inline filter back up. Fuel comes out petcock strong and new inline filter. Any ideas, any help would be appreciated.

[@tylerganton429]

Wow very helpful. I'm taking my carbs in to a professional

[@Chrisk1738]

I have a mini chopper I wanna upgrade to bigger cc engine atm it has 110cc Any ideas what should I put

[@pinoyguy1659]

What 'bout stuck up airscrew that cant be turned to adjust air mixture,what can you do bout it?

[@sigvicious5599]

My Arctic Cat 650 H1 idles perfectly. But it dies the instant I give it gas. I've removed the carb, disassembled, cleaned in a dip tank, reassembled. Same exact issue. It starts and idles great. Just won't accelerate. This issue started last summer after using it. Ran great one day. Ran like poo the next. I also run non-ethanol fuel.

[@gongascosta]

i have the exact same issue with a yamaha gt50, have compression tested for vacum leaks found one in the crankshaft seal, and she idles but with a bit of throttle it dies, my main suspect is the slide needle because one time i lowered the needle to the 2nd position and would accelerate up to 50% but not idle

[@nazimrh9814]

Same issue, let me know if you find a solution

[@Shaco116]

Hi! Maybe you will be able to give some hint. I have problem with small 140cc engine and Nibbi 24 carburetor. It has a big problem with cold start: I'm not able to start engine with choke. I have to use throttle and then when it starts I can switch on the choke. When it's hot it works like a harm. Do you have idea what I can do to repair it?

[@rmatvmc]

You might have plugged jets. Would be a good idea to take the carb apart and clean it out with carb cleaner.

[@hunterlogan2913]

good clear info!! thanks ~

[@rmatvmc]

Glad it was helpful! Thank you for the feedback and views.

[@markdeeframpton]

What about that mid-body. Also emulsion tube with a worn spot from the needle causing 0-1/4 throttle to rob off of the main circuit.

[@JoshSinnott97]

Im looking at buying a new drz400e in Australia. This will be my first bike. I like the idea I can work on it myself to learn and fix when im away camping. What would you say is the shortest length of time when the bike is not in use that you'd want to be draining the carb? Is it a matter of weeks or is this only relevant up to the 6 month mark? Great video btw 🙂

[@56CrazyCruiserCaddy]

I have an 84 Xv1,000, when I 1st bought it, it ran good. Stored it properly for the winter. Then last summer you need to add throttle so It can still run, when I slowly let go it will die. There is brand new coils and wires on there bcuz one coil retired. And the tank and reverse tank has been sealed and cleaned, have new inline fuel filter and hoses, the pressure of the electric fuel pump is strong. Any suggestions

[@landofsaguaros8330]

My Yamaha Bear Tracker was always my most reliable machine started on the first touch of the start button and then all of a sudden no start. I start the machine at least once per month. I have good fuel flow through the petcock right up to the carburetor but when I open the valve at the bottom of the carb bowl nothing comes out of the carburetor as if it's empty. Any thoughts would be much appreciated thank you

[@rmatvmc]

Have you cleaned the jets inside the carb yet?

[@InTheDirtAgain]

I have a KX250 and a Polaris ATV that both run out of fuel at higher RPMs. Super annoying to say the least. The Polaris is a brand new carb (not from China) and the KX is a fully rebuilt original from a certified tech. Thoughts?

[@siaknijustin]

Your float level could possibly be set too low or your main jet is too small.

[@anthonyoddo8072]

What jetting do you recommend for 2023 kx85, got it brand new from the delaer with a 135 main and 40 piolt air screw 1 1/2 turns out and the bike has a hanging ilde that takes sometime to come down after reving and has a bog off the bottom

[@marshallkaufman3123]

idk but a kx80 runs a 45 pilot and a 155 main from stock

[@jamesworsen1421]

Sounds like it's getting to lean a mixture. With a warmed engine turn out the fuel mixture screw 1/4 turns at a time with a quick rev on the throttle; after each 1/4 rotation until it drops quickly to idle level meaning: doesn't come down below idle and climb back up to idle. Here's an interesting technique: kzbin.info/www/bejne/p2qkY4eCbreprbMsi=gzPDMbTdnnnEZYVq

[@shadow1up]

I rebuilt my carb with brand new oem parts and my carb is still puking gas from the overflow. What could it be?

[@rmatvmc]

You might need to adjust your float height. Check out this video on adjusting the carb:kzbin.info/www/bejne/h5yYkKqKf8eHfrM Hope this helps.

[@alejandromorales7201]

Did you try, removing the float needle and blowing through that gas passage? My atv had some debris in there that didn’t let the needle set in place.

[@jamesstevenson3116]

I’ve had the tiniest plant matter get stuck in my seat which didn’t let the needle fully close. Stick a rolled up paper towel in there or blow air/carb cleaner in it (I just did the paper towel so I could see for sure if something was in there and there was)

[@blade9000100]

Thank you for your help.😁

[@frankmchale6916]

How's things,my carburettor doesn't seem to be getting the fuel to the spark plug,it won't start an even after a load of trying, the spark plug is dry,an ideas??? Much appreciate a reply. Thanks

[@rmatvmc]

The spark plug should stay dry. If it's wet that means your cylinder is getting too much fuel and that's how you foul a spark plug.

[@rz350yam]

So, here’s a new one for me (been riding over 50 years). KTM 250 XC-W would intermittently bog when going over whoops. Rest of the ride, runs fine. The bog would happen for a moment then clear. I found a very small stone in the float bowl. Apparently over whoops it would occasionally plug the main jet, then bounce free. Hence, the momentary bog. I have no idea how it got in there, past the fuel petcock filter or the inline filter in the fuel line. Argh!

[@rmatvmc]

That's definitely odd! Glad you got it figured out.

[@jamesstevenson3116]

Likely accidentally got in there when the float bowl was last off

[@SlimThug78]

I have a 93 yz250 that I've been building for woods racing. Would it be okay to turn the fuel off at the petcock and let it die before I store it? I've been learning everything as I go on this bike so I'm not sure if there's any risk to that.

[@rmatvmc]

Since the gas and oil are mixed on a 2 stroke, if you turn the fuel off and let it run dry you're also starving it of lubrication. You're better off draining the float bowl or using a quality fuel stabilizer.

[@EricTostes]

Hey there, how you doing? My DRZ400e is givind me a issue. When I rev the throttle fast the bike does not go, I mean, looks like the cluch, but I've already change it(the discs and the springs) but it still. If I rev the throttle gently, no problem, the bike runs normally, in high RPM it is ok too. Could it be the carburator?

[@rmatvmc]

Is the engine revving up, but the bike is not accelerating at the same rate? Check your chain and sprockets since you've already done your clutch. I've seen this many times where the teeth on the front or rear sprocket are so worn, they round off and act like a slipping clutch. On the other hand, if the bike is cutting out on hard acceleration, that could be a carb. issue. -Charles

[@williamdillingham5781]

That could be the coil falling on its ass when you apply sudden demand

[@Techumsa]

I've changed the exhaust pipe from a stock pipe to a free flow (I added my own baffle) but idling became very erratic, any clues as to why? It's a Suzuki GZ 125

[@kasparszondaks3655]

bought a new 21mm PWK carb for my 49cc 2Tscooter the at first the carburetor was leaking on higher rpms but now it doesnt start the fuel just leak down the breather tube i have adjusted the float and needle so many times and changed main jets but nothing is working

[@RandyLayton-kg3oh]

How do i adjust a carbator on a kawiskoki fourwheeler bayou bran new

[@sg4682]

My Water buffalo Suzuki GT750 2 stroke (trip) with std Mikuni (CV) carbs. I'm seeing what looks like 2 stroke oil leaking from the overflow pipes (all three) even when the bike is not running. The bike starts easily and pulls like a freight train though. Why does it leak so much oil out these overflow pipes?

[@BobStallmanArchUser]

Is it normal that my carb literaly shoots a gas squirt towards the air filter intake when i hit the throttle ?

[@rmatvmc]

No that's not normal. I'd start with looking at the float and needle in the carb. Make sure the float is adjusted correctly, and that the needle is actually seating properly.

[@RocksNRuts4]

how bout a quad that stars n idels fine, but bogs or stall when i hit the throttle? #3? someone said a bad battery can cause that....

[@LM_Bjorkas]

I had a similar problem with my ktm exc earlier. Believe it or not, switching the old fuel with new fuel fixed it. If you’re more unlucky the problem could be inside the tank, either inside the hoses or filters.

[@_apollo1847]

My ttr 125 it's starting the gas is going through the tube because i checked without the carb on but when i put the clean carb on and kicked it a few times i took it off and no gas was in the float area

[@rmatvmc]

It sounds like you might have buildup in your carb where the fuel enters and goes to the float bowl. If you pull the float bowl off the carb, are you able to force air from where the fuel line enters?

[@_apollo1847]

Ok thanks I'll try

[@andrewpena758]

Howdie! Where can i purchase a rebuild kit for 2008 YZ 250f? Please anybody, thanks

[@rmatvmc]

www.rockymountainatvmc.com/parts/dirt-bike-carburetor-accessories?v=2008-yamaha-yz250f

[@JohnPatterson-c1p]

I have fuel leaking into my oil what could be the culprit? Carbs have been rebuilt (although not really dirty or gummy at all) running non ethanol fuel as well. Smoke comes out of my right tail pipe. I can smell the gas in my oil when I drain it.

[@jamesstevenson3116]

I’m not an expert, but it doesn’t sound like a carb issue but more of a potential crack in case or seal issue

[@krishnabinu4180]

Why it show missing at low rpm on sudden acceleration

[@saveearth485]

My carburetor problem is bogging not taking fuel from main jet. butterflie needle not getting up actually..

[@dustyfarmer]

Bike won't start, fuel pouring out onto the ground, only runs with the choke on? Could be you have an AMAL carby on a vintage Triumph motorcycle and it's working as designed.

[@rmatvmc]

🤣

[@dillerino4568]

I had a backfire through my carb and it blew my carb boot off and now that one carb is absolutely filling my cylinder with fuel to the point its leaking out of the header. The fuel float is not out of measurement and the gaskets are still good and nothing is dirty in the carbs. No idea what happened

[@rmatvmc]

Do you have the fuel mixture screw in the correct position? A lean or rich mixture can cause backfiring.

[@Enjoytheinbetween]

I use ethanol free gas, so much better on the carb.

[@rmatvmc]

Great tip! Thanks for the comment.

[@Deep_ends2]

How do I fix my carburator if it's getting to much gas

[@rmatvmc]

If the carb itself is receiving too much gas and overflowing make sure the float is at the correct height. You might want to also check the needle to make sure it isn't worn out.

[@Deep_ends2]

@@rmatvmc it's not overflowing it's just if I give my mini bike full throttle it slows down and doesn't go faster like it's supposed to

[@rmatvmc]

Might be a clogged jet issue.

[@Deep_ends2]

@@rmatvmc ok thanks I'll check it out today and let you know if it works or not

[@MuhammadHelmyHelmyrock]

Tq bro..

[@MuhammadHelmyHelmyrock]

Clogged n fuel flow..always

[@Lifewjohnny]

What’s the best thing to do if your bike wants to go by itself

[@rmatvmc]

Sounds like your clutch isn't fully disengaging. I would check on your clutch lever free play and alignment.

[@kooperadams1519]

see i’m having issues on my carb, my issue is i can’t even get fuel to fill up the float, if i have fuel flow to carb and bleed line open no fuel comes out so the float isn’t filling up at all

[@jamesstevenson3116]

Could be the float is stuck in the seat or a bad needle, not letting gas enter the bowl. Or something blocking it above, I’ve had a piece tiny piece of o ring come off and be floating around there

[@HIncorporated]

Hello from Canada Eh 🇨🇦 I have an 2008, 883 Harley-Davidson Vero.. I think it's called It's a nice chopper, been to shows ect. Has 890 kms on her. It pours gas out of the carb. The pin may be clogged from sitting for years and years. I take it out when we don't have snow sometimes.. hehe What carb kit do I need ?

[@AmazingBlaze0]

Ever heard of a float that just flops up and down? I can’t get it to stay in a certain spot…

[@rmatvmc]

Your float should be able to move up and down but if the needle is not working properly it can cause issues getting the correct height. We have a great video all about setting float height that should be able to clear things up. We talk about the needle and spring at 0:51 in the video can you can watch that here: kzbin.info/www/bejne/h5yYkKqKf8eHfrM But let us know if you still can't figure out a way to set float height and think something is messed up.

[@starlinreese9206]

Get a Lectron 😛

[@jeffharbison6689]

Says the guy who can’t dial in a carburetor

[@gildardomagallon]

Sooooo, get a NEW carb because there are many parts that kits won’t come with lmfao

[@maniacswin]

I have a 2012 250cbr. It doesn't get much use and likes to sit for a long time before getting ridden. I recently went for a ride when it stopped while I was riding on the road. I had to pull over and turn the engine over again before it happened a couple of minutes later. Do you think that this could fit under the clogged pilot jet?

[@rmatvmc]

Yeah I think the pilot jet would be a great place to start.