Does Your Dirt Bike Bog? 

I should probably do something about the seat cover huh?

This video should go down in history as the absolute best explanation of a carb possible

Affew tips for bogging! you have to diagnose whether its a lean or rich bog. rich bog is when it bogs then gains rpm, lean bog is when it bogs and dies, this may not be the case if your jetting is way off, if your bike used to run good and now bogs or runs crappy I wouldn't touch the jetting as its most likely a blocked jet or something worn like the needle or float valve or air leak, blocked air filter, old fuel, id go through the basic things before touching jetting. Jetting should only be adjusted when your bike is fully warm if its liquid cooled that is when you cant touch the radiator cap, air cooled can be abit harder to tell should be warm enough after a 5min ride. On most modern 4 stroke bikes they have pumper carbs which has a mixture screw, easy to tell twist the throttle and it should squirt fuel into the intake also the mixture screw is normally underneath if unsure look your carb up online, clockwise is leaner anti-clockwise is richer (older farm 4 strokes or pitbikes normally have 2 stroke carbs). 2 strokes have an air bleed screw which are normally located on the side of the carb clockwise is richer anti-clockwise is leaner. if u have a lean bog u can try to richen the mix screw or richen the needle by raising the needle which means lowering the clip or bigger main jet. a rich bog is the opposite, if its a lean bog it can be clogged jets and if it dies after a couple seconds of wot not straight away then it can be the float height or clogged fuel filter. Only boggs over bumps or jumps could be worn fuel needle that leaks with vibration causing the bike to flood. Bike doesn't start at all and can smell fuel float could be stuck, can just hit the bowl with a screwdriver saves taking the carb to bits, but if it happens often would be worth pulling apart and cleaning. If it only runs on choke your idle jet is clogged, if it runs better on choke you need to richen the circuit its running on. Depending on what stage of the needle your bike bogs at will tell you what you will need to adjust, 1/4 throttle idle jet 2/4 needle, half throttle needle and main jet, and full throttle mostly main jet, obviously this should just be used as a rough idea there are some great places and books that you can read to get a better understanding. Btw If you you are expecting to instantly go wot from idle very fast it will always bog unless you have a newer 4 stroke or efi, if you do have a pumper carb and it bogs when you blip the throttle and jetting is fine you can adjust the linkage on the carb that pushes the diaphragm that squirts the fuel in the carb. Highly recommend buying the mikuni tuning manual explains things far better than I can.

Another video explaining the same problem was an hour and four minutes long. This one... ten minutes. Good job Cameron.

Very good video, spot on! I'm a retried longtime racer and professional engine tuner over 40 years in before I retired last year. The only thing I would just like to mention to go along with this fantastic video for the others watching this video is: The Pilot Screw screw adjustment can work in one of two ways depending on the type of carb your bike has, on some carbs the Pilot Screw is an Air Screw and on other ones it’s a Fuel Screw and they work in opposite ways, see below. 1. On some carbs the screw is actually an Air Screw and the further you turn the screw in it will reduce air introduced into the circuit and make the bike richer at idle and tip in off idle. Turn screw out and more air is introduced into that circuit making bike leaner at idle and tip in. 2. On other carbs the screw is actually the opposite, and is a Fuel Screw so it’s the exact opposite of above 1. when you turn the screw in and the bike gets leaner, and turn it out it bike gets richer at idle and tip in. For both carb types above when adjusting the screw, adjust it slowly as the change in mixture does not change right away you have to be patient , move it a 1/4 turn and let the bike run a thirty seconds between adjustments. What type is my bike Fuel Screw or Air Screw??? This can be tricky to figure out if your carb is on the bike. If you turn the screw so that the motor achieves its highest RPM at idle say it was at 1200 at startup and you turn the screw in and out slowly when the motor is say at 1400 that’s a good starting point. Once that has been found, shut off the bike and look to see how many turns out that point is from the lightly seated all the way in on the screw, don't force it in, just to the point when you feel any resistance. This high idle point should be in the range of 1 to 2 turns out for both types, as more than 2 turns is already max for the circuit, if its not your pilot jet may be too big or to small depending if your pilot jet circuit is effected by design as an 1. Air Screw or as a 2. Fuel Screw as per 1. or 2. above. You can also test off idle response after the high idle point, try to rev the motor off idle and see if your motor stumbles, if it does if your in the 1-1/2 turn range you can move it in or out and see if the response is better. Finally, if the carb is off your bike you can use brake cleaner to blow liquid thru the circuit and change the screw adjustment to see what is which way makes more or lest fuel to come out the circuit. Be careful not to get an eyeball full of brake clean when doing this that way. Regards, Reg Riemer

I've messed with a lot of carbs and I found your video help me tie my existing knowledge together very well. This 10 min video has made me a better small carb tuner. Thank you for sharing and the great imagery that brought it together. I'm working on a 81 fl250 that I just got. It tough because several mods have been done but original carb is still there.

Cam, your the best teacher I've found for small engine troubleshooting. You might consider a teaching career.

All of your videos are amazing. You take the time to explain why stuff should be done and you actually explain how to do each step of the process. I turn to your channel when it comes to working on my 94/96 RM 250. Thanks for the in-depth look and learn. Keep them video's rolling.

Just discovered this channel not too long ago and I've watched several of your videos. Gotta say man you have some of those most helpful/informative videos I've found. Clean editing and great explanations. Keep up the nice work!

Hey Cam - new subscriber here, but wanted to say your videos are very informative, and helpful. I have a 08 CRF100F and an 08 TTR110E, and your review on the carburetor was very helpful in fixing a bogging problem i have had on the Honda. Thanks!.

Kick ass info m8. Very clear and concise info and the music wasn’t interfering at all. Keep it up bud!

5 years later and I’m still watching your video’s , Awesome work your doing my brother, your helping so many people with you video’s.

I've watched 3 minutes of your channel and I've learned more about my engine than any other video on RU-vid lol thanks for bring so detailed! You gained another subscriber within minutes!

From A to Z troubleshooting of a bogging down engine.The best on RU-vid! Keep the good work!

damn dude this is the most comprehensive and easy to understand carb lesson I've seen. Thanks man! I'm saving this one for future reference.

it’s crazy how i’ve been watching your brother on his car videos now i got a dirt bike and watch all yours good stuff man keep it up

Your videos are so simple to understand and right to the point. Thank you so much for all your time and effort!

Dude u just saved my pit bikes (ttr 125) life thaks dude!!

This video is the best video for fixing up your carb! I have a little 125cc quad that was bogging so bad when I gave throttle, all my mates said it’s either the slide or air/fuel screw. But I didn’t think it was any of that as it ran good before, and after watching this I realised that my float was out of line (running too lean) and I liked the fact how he said that bumpy roads after can stuff a float up, and that made perfect sense as the day it started playing I was out on the bumpiest road ever. Cheers mate, keep up the good work!

Thank you so much!!!! The bike set for 30 plus years!!!! Runs amazing now!!! It was the air gas mixture screw this whole time the guy I bought it off of rebuilt the carburetor and he didn’t have it set right this video is awesome

Love how he explains everything and goes into detail about what does what soo helpful!

This was so helpful. Thanks. My 2011 wr450 was bogging and running rough and when ever I tiped it over just a bit it would piss out fuel. And he was right. The floats were too high

Great info on measuring float height. I have a vintage bike I cleaned up the carb on years back that needs re adjustment/cleaning so this is super useful.

I'm at my 125cc Apollo db37 for about 3 years now didn't know nothing about bikes but i had a passion and eager to learn so I did videos like this definitely helped me years ago when I was coming up but not riding for about a year some change I'm back here to get my basics in order

Amazing videos! I love when people tell you the why what and hows of how to do something. Not just this is how you do it.

Okay, I'm 56 years old. Been riding since I was 6. Have had 84 bikes so far. Owned a Yamaha Dealership. Never had this explained so well. Damn dude! Cameron, is there a way to graft a CRf150R rear swingarm, wheel disk brake, etc. onto a CRF150F? Not too concerned with cost. Just want the best CRF150F I can build (and race). Yes, there is a class for these locally that does NOT include the CRF150R, but you can modify the F model all you want! Any suggestions would be appreciated!!

One of the best carb videos on RU-vid.

Thanks for sharing this, so helpful, finally got my pit bike running properly! Don’t know which one of the things worked, just did them all plus took spark plug cap off and recut HT lead.

I like your systematic approach from the easier to chech and fix to more hard to access root causes. I wish I knew it 5 years ago :-) . It seems the exposion in UV light made not only plasics and seat cover, but also handlebar protector fragile.

I appreciate all the replies to my comment. Thank you guys! And thank you Cameron!!

I've done many things carb related on my dirtbike before, but I've never heard about checking the float height. You really have some mad skills when it comes to dialing in the carb for optimum performance

Your vids are deadly, couldn't be better quality and explained so anyone can understand it. Keep it up!

also check your fuel lines and filter, i mustve taken my carb apart 10 times before relizing my fuel line was kinked and not allowing enough fuel through

Awesome video. I'd add just one thing; for the diagnosis, it's easier to pull the air filter first than the carb - a dirty/blocked filter might give the same symptoms as a blocked jet or badly adjusted float. Other than it's pretty much the same method I use in the shop :P

Best carb vid on RU-vid, hands down

This video is amazing....you aren't acting like a You Tube wannabe and your explanations are so concise and easy to follow. Even though a two stroke is supposed to be so easy to work on....there is sooooo much that the average person hasn't got a clue about......me for one. Thank you and can you make loads of vids please covering the most common problems with Two Strokes...?!?

If you can see the drain tube on your bow at the bottom, bend the clear tube up to the side of bowl and undo drain screw in the bike petrol on. The fuel will come up the tube and find its level which should be horizontal where carb bowl comes apart. Very simple plus accurate. Adjust and recheck if needed.

Great video! But I think you could have also gone into needle height adjustment also. That plays a big role on the main jet also. Again good video. Helped me remember fine tuning tips.

So informative! so many videos leave out important stuff like explaining how you would have a rich or lean environment. Good work!

Ttr 225 was doing the exact same thing, this helped so much man, thanks!

Thanks this really helped me fix my bike

Two things I would add. One, take a Nickel round wound guitar string and put it through the jets like a super small bore brush. Then blow them out. It JUST worked for me with a snow blower carb this week. Also, after you remove the main jet, remove the main jet emulsion tube and blow it out while you're in there. Just saying. Great videos. I watch them all the time.

My son and I are going to hit this check list next weekend. Thank you!

wish I would have found this video about 2 weeks ago. I had just got my carb tuned last night. this video would have saved me some time

Keep up the good work!

Really helpful video 👌

Very helpful. I did all the stuff you said and it works well now. I only had one small spring left over. Don’t know where that came from, but it seems to work without it. 😃

Great explanation, only one I found as thorough as you ! Well done

Thanks ! My floats must definately be low. Overflows fuel sometimes onto the trailer during transport.

2:00 That plug looks extremely rich in the video lol.

One of the best video's I've ever seen. Thank you!

This guy is an absolute ducking legend bro we need more people like you in the motorbike community 👍

The float height also sets the fuel pressure on gravity-fed carbs. If there is too much fuel in the bowl your pressure will be higher and that's why it runs rich and runs out the overflow because of the physical amount of fuel. Too low and you don't have fuel pressure pushing up into the jets and it runs lean.

Just did this and found it was my float now its pissing fuel out of the overflow....

I know I’m late. I have a drz125 and It turned out i was adjusting my air mixture screw . I was really trying to adjust my idle speed. I watched the video now it runs good. Thanks man. Subscribed!

Thanks for the super video, you get right down to business and didn't waste time with stories. Awsome video. Thanks a mill👌

Now I have a better idea of why my WR idles like crap. I'm still not sure why it's so hard to start though. Thanks for explaining the float and jets. Maybe at some point, you could do an entire video on each piece of the carb and problems each piece can create.

My TTr 250 only does this on the first rev after starting it cold.

I appreciate your method of explaining the details of what everythings function is. thank you.

Clear direction Easily understood Great video big Guy💪✅

Love the thumbnail lol😂

When you say -"If your bike has a fuel filter". Shouldn all bike run with a fuel filter? In my mind running without a fuel filter is a recipe for trouble with your carb

Super helpful. Learning how to do my own maintenance on my Yamaha and this video was very helpful. Thanks.

Very informative video. Well done brother. Helpful for a noob like me!

It only bogs when I’m in gear and give it a bunch of throttle, yes mine is carbureted and it’s a high output, does anyone know the problem

Thought the thumbnail was a slightly altered Romanatwood

My wr450 bogs quite hard. And this video has inspired me give these tips a try thank you well explained

The best explanation video I’ve ever come across, good stuff

My fuel screw is gone where can I find some screws

What happened to the seat cover?

Thanks for explaining the carb float settings and how to adjust...

Thank you so much. I just sold my Crf450 and bought 2 85cc 2 strokes that had this exact problem! After watching this video I regret my decision a little less 🥲

My 90 cc 4 wheeler has this same problem and I've done everything you've suggested in this video and it still bogs. It idles great on its own and when the back wheels are held off the ground it goes full throttle without bogging, does anyone know what my problem could be

"clean the Jets with a dust off can..." What about damn carburetor cleaner?!

Never knew this trick awesome video thanks for the knowledge!

Im so glad i found your video! I just got my ttr 125 back from my mechanic and within a couple days of riding it, it began to bog out. Im almost certain that the problem is gonna be a clogged main, and, or pilot jet cause i did notice some bits of dirt in the fuel tank, so i siphoned the fuel out of the tank and to my surprise it was more than just a bit of dirt in the tank, it was alot! Im guessing that i didn't quite get it all out, and now the pilot jet is clogged. Thanks to you 🙏 and your wonderful video, i now know what to do to fix the problem.

Ya cause my bike don't even idle right now

Ha! Guessed the new video ;) What did I won :D

Really appreciated this video. My 02cr250 just started having bogging problems today on some trails.

Kickstarting it from in front of the bike, that's pretty cool! Badass, never would've thought of that

Knows nothing I didn’t know jets were in dirt bikes Pro//boy are you serious

Best carb video I’ve seen by far.

Awesome video. I never knew a float off can cause this thanks you so much

Hands down, tne of the best carburetor field repair explanation

Good Video! And such a charm to get that carb out. Working on a KTM 640 LC4 Duke, with a Keihin FCR 41 MX .. it's a cramp to get onto it, the fuel tank needs to be removed each time.

thanks man! im only 12 and i work on my klx125l i had a issue with it not idling it was the mixture screw and it didn't return to idle that well and i'm still trying to figure that out but this helped cuz it bogged too but your vids have helped me solve every problem on my bike. thanks!

Great video! Most straight forward carb video on here! Give me FI, a laptop and tuner and I'm good to go. Give me a carb, and I'm watching your video!

Thanks for the help man worked perfectly on my 2007 ttr125 :)

My sons TTR runs great after watching this and doing the same things. Thanks Cam!!

So glad I found this video my 2010 Kym 250sxf is bogging hard when I start it an whilst riding when I start slowing down to corner of something it just stalls out

Awesome video cameron.good detail

That is a well done and useful video. Very detailed explanations of everything thanks

Thank you this vid helped a lot i just was done finishing fixing my dirt bike

I just bought a WR450F that had some mods done to it ... it will only run when you keep the choke on. They told me it needed to be rejetted so thanks for explaining the jets like you did it might help me out fixing this prob...

The best explained In detail video out there.

Wow great explanation ! I had same problem with my dirt bike i couldn't solve it. Thank you so much

Your clearly knowledgeable about fixing Dirt bikes of all kinds.

Great video, just got my bike and had the problem of it bogging when the choke was in. this helped alot!

Ur my hero right now I've been struggling years for someone to explain something to me in a decent manner for me to understand what they mean

dude best simple carby explanation ever