You know what man, 5 years ago I custom built a big 650 single with an FCR from scratch with no baseline for jets. Took me weeks and a lot of angry neighbours! I then shortly after got squashed by a kid in a new car and the bike has sat in the garage since. Well iv decided to look at fixing and completely forgotten the jetting orders, in fact was even scared pulling the carb apart. This vid has instantly refreshed my memory, no bullshit, no unnecessary chit chat, straight to the point with all details covered. For what's it's worth here's one random guy on the Internet who is extremely grateful for your time. Now to see if the beast still has a heartbeat... And annoy the neighbours some. Hopefully.
The biggest thing I learned from this is I need an AFR gauge. Of the dozens of jetting guides I've seen, none mention this very helpful tool. Seems like everything else is guesswork and an art. Thanks for the tips!
This is by far the best video and information in general I have ever come across about FCR carbs and I have done a ton of research in the last few years so kudos to you for making it and whoever gave this a thumbs down must have not been very intelligent and probably couldn't follow it. In order to learn how to do something good you need to have an understanding of how it works first and this is what you showed us in the video and I'm sure it will help me be a better tuner. I have been switching my bike between stock and a big bore kit and also from both of those to a high compression piston and each time I have to make jetting changes. My bike ran perfect with the stock piston but ever since adding the HC piston I'm having a hard time getting it dialed perfectly in. I finally have it almost there but I'm still getting some weird surging idle. I have changed every jet and tried dozens of combinations and also rebuilt the acc pump diaphragm which helped with an off idle bog I was getting when twisting the throttle fast but the weird surge is still there slightly. It gets better if I turn down the idle but then the bike is hard to get started when hot and also stalls occasionally. I also noticed if I tilt the bike on it's side while it's doing it it goes away. And lastly it gets only noticeable when the bike gets real hot so after running for a good amount of time straight. It seems like the very very slightest twist of the idle makes huge changes so it's hard to get it dialed in. Any help would be appreciated? Thanks again for the video!
@@EmersonRaceworks Just awesome.. On my '05 WR450 runs awesome but lots of popping on Decel, 170 main 48 pilot 2 turns out on aircscrew. Nothings clogged should I try 50 pilot 175 main?. 2000ft elevation.👍
Amazing ! Clearly explained ! I was lost about lean conditions at slow work on my 450, almost completely lost between hot and cold start, and thanks to you I discovered I switched hot and cold start valve on my FCR41 !!! That explain and make sense with issues I’m facing. Really nice video, best one on TH-cam !
Thank you Neal. I have had so many people tell me bits and pieces of information about how to tune a mx carb, but no one has ever been able to give me the whole picture. This is very informative and well done. Cheers brother!
I have to agree with all of the comments - incredibly informative video about carburetors and fuel/air flow. I learned more from this video than any other!! THANK YOU for making and sharing it.
Thanks for taking the time to put this together. I've been trying to fix a 10% throttle hiccup on my 525SMR and this is the first mention I've seen of emulsion tube and/or metering rod wear.
Looks like this became an obsession to get the CRF running as perfectly as possible given changing weather and atmospherics and to understand exactly what was going on in the carb at different throttle openings. Very well explained and logical approach, the overlaying of the jets on the scale diagrams added to the clear and thorough presentation as did the photographs of the worn parts. Excellent educational video, well paced and presented. Would be interested to see how you mounted the sensor probe?
That’d be great to see also if you could provide a link to the AFR gauge you used that would be awesome. I’ve never heard of that device before but it sounds like a great tool to have. 🤙
Awesome presentation man.. I have a major issue with my sm 04 crf450X plated for the street also here in PA. The initial hit on my throttle eyelids a hard bogg but slow increase in throttle it's fine. If my little brain interpreted your information I think I need a smaller leak jet hole. I'm going to make the adjustment and I'll let you know how it works out if you like. Thanks so much for the content man! Your doing great work
Oh and special thanks for explaining the leak jet! I had a pretty good idea how the rest works cause I had a shit time trying to figure out why my yz450 was hard to start and then run like crap and overheat so I've spent a bit of time puzzling over that same style carburettor. But the leak jet was still a mystery to me till now. My problem ended up being a leaking hot start plunger.... I hope! I'm still putting it back together, good video 👍
Great video man…super well done!!! I really appreciated your well researched, methodical, and scholarly approach you used with the mechanical drawings while explaining the carburetor circuits and carb tuning theory. Everything you said made 100% sense once you explained everything. This video is a great resource and I’m sure I’ll end up coming back to it a few times as I jet bikes in the future. 🤙
Well done. Thank you!!! To get more views, you might want to tag 250 four strokes and maybe Keihin FCR carburetor. I've been searching for a video like this for months. YOU have delivered. Great stuff.
such a well informed video on this carb, ive just completed a street legal crf490 build and have been dealing with this nightmare and im bored of having to remove the carb at this point😅 im getting very close but as you say getting the cruise right without hesitation is abit tricky what were the jets and needle specs you ended up with out of interest? also going to get myself an afr gauge so theres no doubt left, ive used afr’s on my cars in the best but didnt think the stock crf electrics would power it.. so good to know this is possible also last thing is could you provide a link to the guide youve made to make the process abit easier when working at the bench cheers for the help, this is an awesome guide
Thank you,after watching the video i menaged to tune the carb properly on my Crf 250r,it was easy to cold start it,usually one kick ,but after the engine warms up it was i nightmare..It was running rich..
Einstein said "if somone can not explain complicated things in simple way, its means that he does not understend it" Great work. Can you share how You had instal the AFR meeter with it sensor?
I have watched so many vids on how to clean or rebuild these FCR carbs, but very few explain (or do so what any degree competence) what each circuit does with interaction, and what to look for to tune, particularly the air/fuel ratio. And the fyi regarding the emulation tube, and what the hot start does... excellent! I have a few questions: 1- would you post a link to your Tuning Order document? 2- how would elevation affect the air/fuel ratio in terms of target ratios? I'm assuming 12.5 / 13 is still target, just what jets and such it takes to get there would change? (I live at 3k ft and ride between 3k and 9k ft.) 3- what gauge/instrument were you using and how/where did you connect it? I'd love to see a vid on just that :) Thank you for an amazing & very helpful vid.
This is awesome. Some one that explained all the circuits and jets in the carb. I would like to know what fuel ratio gauge you have and where did you get it.
Wow, this is such a great instructional video! I was going to ask the same as a few of the other commenters, is there a pdf copy of the tuning order? I was kind of hoping you would have some other video's of similar nature, I can tell you are a great teacher! 👍
Most detailed FCR video I've seen! Any advice or could you make a video on adjusting the AP timing screw/and leak jet? My ktm 525 bogs a bit off idle and I'm not sure what adjustments to make to help. Cleaned everything and got it spraying/working as it should, just need to fine tune it. 42 pilot, 1-1/8 on air screw as J/D jet kit recommends.
Great vid. So what would it mean if I have a slight miss fire on the idle AND choke circuit? I waa under the impression that the choke corcuit was its own circuit of air and fuel? When I got this 2006 CRF250R it had a 40 pilot in it has a 172 Main and the needle clip is in the third position from the top. Well I had to go up to a 45 pilot and move the needle clip down to v slot from the top to get it to start and then run smooth at warm up from the idle circuit to the mid-range. Now when I put it on the choke circuit to start it when it's cold there's a slight Miss and then when it's warm it still has the same Miss on the normal idle circuit. I believe that the previous owner put in all balls jetting kit in it because of the number engraved knob headed pilot fuel screw as well as it had a silver number 40 pilot in it. That kit comes with screws pilot jet needle and the adjustment screw for the pilot fuel screw and for carburetor Bowl screws. With a 45 pilot when I screw in the fuel screw at idle after warmed up it will start to die off and stall out and a half Turner below out from seated. But I don't really notice a whole lot more after 2 or two and a half turns out. So I'm contemplating I'm going back to the original stock needle as I'm not sure if this all balls needle is quality enough. You can find a video of my issue on this bike on my channel as it was just uploaded the other day. If you've gotten this far thanks for reading and I look forward to your reply. Andrew C
Great video, super helpful. Show us a video on how to install the air fuel gauge please. Also let me know what model you put on your bike. Everyone will love you for it. I'm assuming you have to weld a thread fitting on to the exhaust pipe to accept the sensor?
Popping on decel is sign of the lack of an acv circuit (not needed on racing carbs, only street bikes have it). Kudos to the creator, this is the first time I see someone tuning an FCR (or carb generally) properly.
@@panosvougiou Can the carburetor be somehow tweaked to not induce backfiring even without air cut valve? Spend almost whole day tuning polini pwk30, thinking my pilot jet was too lean, which is not the case evidently.. if I go rich enough, the backfire's almost gone but the bike won't start, cause it's too rich
@@peshhhiify hey, please refer to guides on how to adjust your idle speed/ims screw, it's a relatively easy process. A bit of exhaust popping is expected when your idle mixture is set properly.
@@panosvougiou Thanks! I finally discovered, that the problem was unmetered air passing through bad sealing after the carburetor. That's why a i wasn't able to tune it properly, especially on the pilot circuit, where it got the most pronounced..
Good video, one of the best I've seen on how a carb works and the air fuel ratio guage was a bonus. I'm looking at purchasing an afr meter to sort out the afr on two of my bikes. I do have a very nice digital carb balancer that has other functions for fine tuning afr etc. but on my v twin its not stable enough to get a steady reading and a colourtune plugh is not fine enough to see the colour change so an afr meter seems to be the way forward?
Hey, would it be possible to get the packet you created. You touched on a lot of knowledge I had but you did a FANTASTIC job of organizing it and creating the proper tuning flow. If so If we could find a way to exchange contact info that would be great
neal, excellent video...i've been fiddly with the carb on my 450x for 6 months...can you tell me where you got those awesome FCR diagrams? i found that the little brass 'ball' that apparently seals the top of the hotstart pathway leaks air and dirt into the carb body....
First off, fantastic video and probably the best explanation of how a carb works on the internet. Second, what are your sprocket sizes? I recently converted my 08 450R to street, and Im curious what works best for you?
I fit a 15 tooth on the front, and a 44 tooth on the back. Stock internal gearing. With this setup its perfect for daily street driving. it can operate at ~65mph no problem without over revving and i've had it up to ~98 tapped out.
Thanks for your video Neal. Excellent! I want to try a new emulsion tube in my FCR on my KX450F. On the Kawi parts diagram the only part I can find which might be it, is something they name the "Nozzle main". Part 49121. The main jet screws into it. Is that the emulsion tube?
The fuel flow diagrams I got directly from the service manual that comes with the dirtbike from Honda. I just made larger copies of them individually to use for the video, and highlight on. And Thank You.
Hey man thank you for this very helpful video. I’m trying to fix my 04 crf450r and I replaced the jets and I have to put the pilot screw all the way inside if I turned it less than half turn it turns off and it won’t start again. All the parts I got to rebuild the carburetor are original Honda. What should I do now?
Great video! I just got done putting all the street legal stuff on my 450, and I also live in pa. I go the bike from my brother in Texas, and I was wondering if you could list the jet and needle sizes you used.
great visual explanation. I have an FCRMX 41 and when I start from 2 turns out and tighten (lean) it revs up all the way till seated. Conversely, if I start from 2 turns out and loosen (richen) it will slow down till it stalls at about 3.5 turns. From what you said, i need a smaller pilot jet. But I just looked at i'm already at 42. I've always run 45 or 48 with other bikes/quads using this carb. Any reason why I might have to go smaller? The carb is from an 07 KTM 450sxf but it's installed on a 2007 Suzuki LTR450 Race quad. (which was injected). Thanks!
Hi. Awesome video sir, very informative. I just bought a 09 CRF 250, but struggle to get it to run right. the motor has just been overhauled at a professional shop by the previous owner, but the bike is impossible to kick start. starts fine by roll start at about 5-6 mph. When the motor is warm it starts easily by rolling, but still no kick. The bike idles very high tho and dies when adjusting the idle speed screw. The carb has an aftermarket R&G float bowl, and the previous owner said that may be the problem, but do you think so? or should i just try to check the float hight, pilot screw and then jetting? Thanks!
I would completely disassemble it and clean it as I've done here. Then verify the stock jetting Honda prescribes for your year is in there. Then if it still runs bad then make adjustments. And the aftermarket fuel bowl.... just make sure the float height is where it's supposed to be. Whether its stock height or different as requested by manufacturer.
Great work, I have been struggling with my son-ln-law's 450, had old fuel in it, cleaned it out replaced all the jets, runs with choke but dies as soon as the throttle is just touched also dies when choke released. Now to watch this and see if I can fix it for him (I'm an old Yamaha XS1100 rider)
You know what man, 5 years ago I custom built a big 650 single with an FCR from scratch with no baseline for jets. Took me weeks and a lot of angry neighbours! I then shortly after got squashed by a kid in a new car and the bike has sat in the garage since. Well iv decided to look at fixing and completely forgotten the jetting orders, in fact was even scared pulling the carb apart. This vid has instantly refreshed my memory, no bullshit, no unnecessary chit chat, straight to the point with all details covered. For what's it's worth here's one random guy on the Internet who is extremely grateful for your time. Now to see if the beast still has a heartbeat... And annoy the neighbours some. Hopefully.
The biggest thing I learned from this is I need an AFR gauge. Of the dozens of jetting guides I've seen, none mention this very helpful tool. Seems like everything else is guesswork and an art. Thanks for the tips!
This video sets the standard for knowledge level for pumper (FCR) carbs. Bravo. 👏
Thanks mang! 🍻
Emerson Raceworks where did you get the air/fuel mixture gauge mine is 2004 crf450r pinched to hot cam 490
This is by far the best video and information in general I have ever come across about FCR carbs and I have done a ton of research in the last few years so kudos to you for making it and whoever gave this a thumbs down must have not been very intelligent and probably couldn't follow it. In order to learn how to do something good you need to have an understanding of how it works first and this is what you showed us in the video and I'm sure it will help me be a better tuner. I have been switching my bike between stock and a big bore kit and also from both of those to a high compression piston and each time I have to make jetting changes. My bike ran perfect with the stock piston but ever since adding the HC piston I'm having a hard time getting it dialed perfectly in. I finally have it almost there but I'm still getting some weird surging idle. I have changed every jet and tried dozens of combinations and also rebuilt the acc pump diaphragm which helped with an off idle bog I was getting when twisting the throttle fast but the weird surge is still there slightly. It gets better if I turn down the idle but then the bike is hard to get started when hot and also stalls occasionally. I also noticed if I tilt the bike on it's side while it's doing it it goes away. And lastly it gets only noticeable when the bike gets real hot so after running for a good amount of time straight. It seems like the very very slightest twist of the idle makes huge changes so it's hard to get it dialed in. Any help would be appreciated? Thanks again for the video!
What kind of fuel are you using? High compression pistons typically need higher octane fuel from my understanding. Also what does your plug look like?
best carb video on TH-cam 👍
Exactly! I learned some crucial stuff from this vid. Thanks Neal, great explanation!
@@hansottosmotos Thank you both!
@@EmersonRaceworks Just awesome.. On my '05 WR450 runs awesome but lots of popping on Decel, 170 main 48 pilot 2 turns out on aircscrew. Nothings clogged should I try 50 pilot 175 main?. 2000ft elevation.👍
Amazing ! Clearly explained ! I was lost about lean conditions at slow work on my 450, almost completely lost between hot and cold start, and thanks to you I discovered I switched hot and cold start valve on my FCR41 !!! That explain and make sense with issues I’m facing.
Really nice video, best one on TH-cam !
Finally found someone who can explain a carby in a way anyone can understand, thank you.
this has got to be the best, most in depth FCR explanation I have seen. I need to tune my carb on my KTM and this is perfect info
One of the best carb videos I have seen yet
Thank you, I appreciate it.
Love it. I have 4 CRF250R (2006-2007-2008) and they all need a bit of love in the carb tuning area. Very well done and concise. Thank you!
Thank you Neal. I have had so many people tell me bits and pieces of information about how to tune a mx carb, but no one has ever been able to give me the whole picture. This is very informative and well done. Cheers brother!
Thank you very much, I'm glad I was able to help out quite a few folks. 🍻
I have to agree with all of the comments - incredibly informative video about carburetors and fuel/air flow. I learned more from this video than any other!! THANK YOU for making and sharing it.
5 year old video and still getting good info from it props for putting together such an informative vid learned a lot
Thank you, I'm glad this video is still helping people.
Thanks for taking the time to put this together. I've been trying to fix a 10% throttle hiccup on my 525SMR and this is the first mention I've seen of emulsion tube and/or metering rod wear.
Great video for someone who has no clue about these carbs. I like the cutaway diagram showing fuel and air flow, awesome documentation to have!
Looks like this became an obsession to get the CRF running as perfectly as possible given changing weather and atmospherics and to understand exactly what was going on in the carb at different throttle openings. Very well explained and logical approach, the overlaying of the jets on the scale diagrams added to the clear and thorough presentation as did the photographs of the worn parts.
Excellent educational video, well paced and presented.
Would be interested to see how you mounted the sensor probe?
Once the weather warms up a bit here I'm going to make another video of how I got the AFR gauge mounted. A lot of people have asked for that.
That’d be great to see also if you could provide a link to the AFR gauge you used that would be awesome. I’ve never heard of that device before but it sounds like a great tool to have. 🤙
Awesome presentation man.. I have a major issue with my sm 04 crf450X plated for the street also here in PA. The initial hit on my throttle eyelids a hard bogg but slow increase in throttle it's fine. If my little brain interpreted your information I think I need a smaller leak jet hole. I'm going to make the adjustment and I'll let you know how it works out if you like. Thanks so much for the content man! Your doing great work
Oh and special thanks for explaining the leak jet! I had a pretty good idea how the rest works cause I had a shit time trying to figure out why my yz450 was hard to start and then run like crap and overheat so I've spent a bit of time puzzling over that same style carburettor. But the leak jet was still a mystery to me till now. My problem ended up being a leaking hot start plunger.... I hope! I'm still putting it back together, good video 👍
John Richardson
How to understand, that hot start plunger is leaking?
I'd agree....great explanation on carb operation and jetting effects!
How has this not got a million views!
best video on this subject i have ever seen. Thank you.
Great video man…super well done!!! I really appreciated your well researched, methodical, and scholarly approach you used with the mechanical drawings while explaining the carburetor circuits and carb tuning theory. Everything you said made 100% sense once you explained everything. This video is a great resource and I’m sure I’ll end up coming back to it a few times as I jet bikes in the future. 🤙
Dang great rundown. Helping me get more In depth with the carb. Thank you!
Good job explaining all that, good diagrams, thorough, easy to understand, thumbs up.
Great video and visual imaging! Thanks for making it easy to understand. Great Work.
do you have a link for the pdf file you are holding? that would BE awesome! thanks for the video! so helpful!
I just came across this video and it's so insightful. Was going to ask the same question about getting a link to that document.
Very educated look inside the workings of the carb and well explained! Good job on the research and details. Thanks!
Brian, Thanks Man!
Neil... You Are My HERO!!!!! You just saved me months of research! Thanks Brother!
yea this is great. thanks a lot man! just bought a 06 crf450r and i took a vow to never use a mechanic.
Great Video!!! Hands down best FCR carb video I've seen yet.
Great video. Can you please offer up the reference documents you were using? These look very useful.
Well done. Thank you!!!
To get more views, you might want to tag 250 four strokes and maybe Keihin FCR carburetor. I've been searching for a video like this for months. YOU have delivered. Great stuff.
Thank You, and I did just now update the tags for people to find easier. I appreciate the input.
Very educational. I run a mikuni tm40 but most of the proces is the same. I consider mounting an AFR gauge myself to finetune
This a fantastic video. Really great explanation and very well filmed. Thank you for taking the time to put out such an awesome video!
Thanks dude!
this video is the bomb. badass tutorial. I have learned so much about my own fcr carb now.
Im really glad it helped, that was my whole intent. Cheers
Neal Emerson hey u have the part number of the a/f gauge u used
I got it from Innovative Motorsports website www.innovatemotorsports.com/products/mtxl_plus.php
such a well informed video on this carb, ive just completed a street legal crf490 build and have been dealing with this nightmare and im bored of having to remove the carb at this point😅
im getting very close but as you say getting the cruise right without hesitation is abit tricky
what were the jets and needle specs you ended up with out of interest?
also going to get myself an afr gauge so theres no doubt left, ive used afr’s on my cars in the best but didnt think the stock crf electrics would power it.. so good to know this is possible
also last thing is could you provide a link to the guide youve made to make the process abit easier when working at the bench
cheers for the help, this is an awesome guide
Thank you,after watching the video i menaged to tune the carb properly on my Crf 250r,it was easy to cold start it,usually one kick ,but after the engine warms up it was i nightmare..It was running rich..
Excellent video it's helped my understanding of these carbs
Wow....u are a GOOD TEACHER
Seriously great work. Thank you!!!
Thank you, I appreciate it 🍻
EXCELLENT video. Thanks for taking the time to produce it and post.
Einstein said "if somone can not explain complicated things in simple way, its means that he does not understend it" Great work. Can you share how You had instal the AFR meeter with it sensor?
First Class Explanation!
Awesome video man. helped me troubleshoot the FCR on my YZ250F
I have watched so many vids on how to clean or rebuild these FCR carbs, but very few explain (or do so what any degree competence) what each circuit does with interaction, and what to look for to tune, particularly the air/fuel ratio. And the fyi regarding the emulation tube, and what the hot start does... excellent!
I have a few questions:
1- would you post a link to your Tuning Order document?
2- how would elevation affect the air/fuel ratio in terms of target ratios? I'm assuming 12.5 / 13 is still target, just what jets and such it takes to get there would change? (I live at 3k ft and ride between 3k and 9k ft.)
3- what gauge/instrument were you using and how/where did you connect it? I'd love to see a vid on just that :)
Thank you for an amazing & very helpful vid.
Awesome video brotha jetting was totally confusing, this cleared up a heck of a lot. Thanks for taking the time to put it together.
Love your detailed explanation. Where do you get the gauge setup and how to connect it to the bike?
This is awesome. Some one that explained all the circuits and jets in the carb. I would like to know what fuel ratio gauge you have and where did you get it.
I also would like to know the answer to this question.
I am very impress with your recaerch and analysis , well don bro
Thank You!
Hi, very helpful,One question, if the pilot screw is all screw in, the engine must die?
Wow, this is such a great instructional video! I was going to ask the same as a few of the other commenters, is there a pdf copy of the tuning order?
I was kind of hoping you would have some other video's of similar nature, I can tell you are a great teacher! 👍
great video . could you show a close up pic of install location of the meter sensor?
Man, great explanation, how do we get a copy of those documents you put together? Would love to review it for deeper understanding.
Most detailed FCR video I've seen! Any advice or could you make a video on adjusting the AP timing screw/and leak jet? My ktm 525 bogs a bit off idle and I'm not sure what adjustments to make to help. Cleaned everything and got it spraying/working as it should, just need to fine tune it. 42 pilot, 1-1/8 on air screw as J/D jet kit recommends.
Great vid. So what would it mean if I have a slight miss fire on the idle AND choke circuit? I waa under the impression that the choke corcuit was its own circuit of air and fuel? When I got this 2006 CRF250R it had a 40 pilot in it has a 172 Main and the needle clip is in the third position from the top. Well I had to go up to a 45 pilot and move the needle clip down to v slot from the top to get it to start and then run smooth at warm up from the idle circuit to the mid-range.
Now when I put it on the choke circuit to start it when it's cold there's a slight Miss and then when it's warm it still has the same Miss on the normal idle circuit. I believe that the previous owner put in all balls jetting kit in it because of the number engraved knob headed pilot fuel screw as well as it had a silver number 40 pilot in it. That kit comes with screws pilot jet needle and the adjustment screw for the pilot fuel screw and for carburetor Bowl screws.
With a 45 pilot when I screw in the fuel screw at idle after warmed up it will start to die off and stall out and a half Turner below out from seated. But I don't really notice a whole lot more after 2 or two and a half turns out. So I'm contemplating I'm going back to the original stock needle as I'm not sure if this all balls needle is quality enough. You can find a video of my issue on this bike on my channel as it was just uploaded the other day. If you've gotten this far thanks for reading and I look forward to your reply. Andrew C
Excellent detailed video for fcr carb
Got a 02 crf450 going sumo but the carb tune has sent me to bed countless times unhappy but A+ with the video time to get a AF Meter
450r🤓
Fantastic video. Thanks from Australia
Wow. I don't think I've ever learned so much in so little time. Thanks.
Wow great video. I've been trying to figure my 07 out. Falls flat when I hit wot fast. If I slowly wind it up it's better.
Great video, super helpful. Show us a video on how to install the air fuel gauge please. Also let me know what model you put on your bike. Everyone will love you for it. I'm assuming you have to weld a thread fitting on to the exhaust pipe to accept the sensor?
awesome video!!! i love the detail!!!! popping on decel is a sign of lean pilot circuit..
Popping on decel is sign of the lack of an acv circuit (not needed on racing carbs, only street bikes have it). Kudos to the creator, this is the first time I see someone tuning an FCR (or carb generally) properly.
@@panosvougiou Can the carburetor be somehow tweaked to not induce backfiring even without air cut valve? Spend almost whole day tuning polini pwk30, thinking my pilot jet was too lean, which is not the case evidently.. if I go rich enough, the backfire's almost gone but the bike won't start, cause it's too rich
@@peshhhiify hey, please refer to guides on how to adjust your idle speed/ims screw, it's a relatively easy process. A bit of exhaust popping is expected when your idle mixture is set properly.
@@panosvougiou Thanks! I finally discovered, that the problem was unmetered air passing through bad sealing after the carburetor. That's why a i wasn't able to tune it properly, especially on the pilot circuit, where it got the most pronounced..
nice and full explanatory! congrats..
Good video, one of the best I've seen on how a carb works and the air fuel ratio guage was a bonus. I'm looking at purchasing an afr meter to sort out the afr on two of my bikes. I do have a very nice digital carb balancer that has other functions for fine tuning afr etc. but on my v twin its not stable enough to get a steady reading and a colourtune plugh is not fine enough to see the colour change so an afr meter seems to be the way forward?
tres bon travail d'explication avec de bons schema, bravo
Wow this is extremely informative.... Very well done 👏
Huge help. Thank you!
Um... This video is priceless. FCR guru this guy.
very informative video. well done.I learned a lot that I was not sure of.
thanx and keep on riding.
Great video! Thanks. Can you give us links to materials and that air fuel gauge setup?
amzing video, really well explained and well thought out. thanks
Nice video! Is it normal to block the air jet with your finger while idling and have nothing happen?
Great video!!! So much useful info
Hey, would it be possible to get the packet you created. You touched on a lot of knowledge I had but you did a FANTASTIC job of organizing it and creating the proper tuning flow. If so If we could find a way to exchange contact info that would be great
cheers mate, thank you so much for great info. YT (world) needs you.. dare to say that much!
Very, very good video 👍👍
amazing job! this is incredibly helpful and well done! thank you for doing this tutorial explanation!
neal, excellent video...i've been fiddly with the carb on my 450x for 6 months...can you tell me where you got those awesome FCR diagrams? i found that the little brass 'ball' that apparently seals the top of the hotstart pathway leaks air and dirt into the carb body....
Really good video man....thanks for posting!
First off, fantastic video and probably the best explanation of how a carb works on the internet. Second, what are your sprocket sizes? I recently converted my 08 450R to street, and Im curious what works best for you?
I fit a 15 tooth on the front, and a 44 tooth on the back. Stock internal gearing. With this setup its perfect for daily street driving. it can operate at ~65mph no problem without over revving and i've had it up to ~98 tapped out.
Thanks for your video Neal. Excellent! I want to try a new emulsion tube in my FCR on my KX450F. On the Kawi parts diagram the only part I can find which might be it, is something they name the "Nozzle main". Part 49121. The main jet screws into it. Is that the emulsion tube?
Great video, the fuel flow diagrams are just what I was looking for. I have looked all over for those, where did you get them?
The fuel flow diagrams I got directly from the service manual that comes with the dirtbike from Honda. I just made larger copies of them individually to use for the video, and highlight on. And Thank You.
Great video. What kind of air fuel meter is that
Hey man thank you for this very helpful video. I’m trying to fix my 04 crf450r and I replaced the jets and I have to put the pilot screw all the way inside if I turned it less than half turn it turns off and it won’t start again. All the parts I got to rebuild the carburetor are original Honda. What should I do now?
Replace your "mid body" o-rings set as well.
Very well explained, you should teach a class.👍👍
Great video! I just got done putting all the street legal stuff on my 450, and I also live in pa. I go the bike from my brother in Texas, and I was wondering if you could list the jet and needle sizes you used.
Very nice video. How is the AF sensor installed?
Great video, good information 👍 thanks for sharing.
Great video! May I ask where exactly you have welded bung for wideband sensor? How close/far from the engine?
great visual explanation. I have an FCRMX 41 and when I start from 2 turns out and tighten (lean) it revs up all the way till seated. Conversely, if I start from 2 turns out and loosen (richen) it will slow down till it stalls at about 3.5 turns. From what you said, i need a smaller pilot jet. But I just looked at i'm already at 42. I've always run 45 or 48 with other bikes/quads using this carb. Any reason why I might have to go smaller? The carb is from an 07 KTM 450sxf but it's installed on a 2007 Suzuki LTR450 Race quad. (which was injected). Thanks!
Very Very Very GOOD VIDEO !!! Great job , Thanks.
Hi. Awesome video sir, very informative.
I just bought a 09 CRF 250, but struggle to get it to run right. the motor has just been overhauled at a professional shop by the previous owner, but the bike is impossible to kick start. starts fine by roll start at about 5-6 mph. When the motor is warm it starts easily by rolling, but still no kick. The bike idles very high tho and dies when adjusting the idle speed screw.
The carb has an aftermarket R&G float bowl, and the previous owner said that may be the problem, but do you think so? or should i just try to check the float hight, pilot screw and then jetting?
Thanks!
I would completely disassemble it and clean it as I've done here. Then verify the stock jetting Honda prescribes for your year is in there. Then if it still runs bad then make adjustments. And the aftermarket fuel bowl.... just make sure the float height is where it's supposed to be. Whether its stock height or different as requested by manufacturer.
Great video!!!
Awesome video man! What were the main changes that you had to do to your carb for the sumo conversion? Im assuming mainly the needle?
nicely done, explained well!
Thanks a lot, my supermoto with a fcr is popping on decel quite a bit trying to figure out why
i agree t.. he makes total sense and u can understand
Great job mate
Very good, intelligent video! Thanks.
Great work, I have been struggling with my son-ln-law's 450, had old fuel in it, cleaned it out replaced all the jets, runs with choke but dies as soon as the throttle is just touched also dies when choke released. Now to watch this and see if I can fix it for him (I'm an old Yamaha XS1100 rider)