Pilot Air/Fuel Screw Adjustment Explained - Multiple Carbs - Part 2

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Aux fuel tank
amzn.to/2WJboTy

[@HTMR]

Pilot jet explained blog post - www.howtomotorcyclerepair.com/how-to-size-your-pilot-jet-pilot-screw-explained/ Aux fuel tank - amzn.to/2WJboTy

[@lorenzjustiniani9489]

Can you make another video showing where the carbtune vacuum hoses being inserted?

[@boxingtips1012]

Wow you are good teacher. Thanks. I am having issue on a ttr110 tried different jets to control bog at full throttle but now I have good ful throttle but no idle and when I change pilot I get full open bog I'm so confused can't get both to be right. I have a air screw and a welch plug do I have both air and fuel screw? I thought u said there is only either or.

[@TheAwmartin]

Royal Vintage Spare A112 Auxiliary Fuel Tank For Servicing Your Bike 300Ml

[@patricksmith6776]

"Every jet size is a 3 - 5% change, approximately, and I also made that number up." And subbed...

[@sirrolfenstein2689]

I did the exact same thing

[@thefurryteddy1018]

As far as carb adjustments, this is definitely the best video ive watched so far. Also explaining how it works. Thanks a bunch. I feel way more comfortable going foward with my 1st attempt

[@rreynolds7355]

You not listen to any other explanation. This guy teaches well explaining and showing what to do

[@Bournefort]

Wow. Amazing tutorial. Your description of the air vs fuel metering pilot screws was extremely helpful.

[@AlexAnyways]

Already liked that video last year when I found it, looking for info about carb and rebuild and tuning but want to say thanks again since I completely rebuild both of my 96 1100 Virago carbs and currently having some issue to tune it well. I looked and dozens of videos but this one, I I look at again, clarified everything. You are very clear and really take the time to visually explain how the carb works. Thanks man! really nice work!

[@sonnyguacena9807]

This is one of the best explanation when it comes to A/F mixture, kudos man!

[@justinwentz5826]

just bought a 1980 KZ750 I’m working on getting it running thanks this has been helpful

[@Sn0wWh0rE]

You might have just saved my bike. Stay tuned! Thanks for taking the time. The most informative video on the subject that I've found. I can't wait to get home and try this.

[@acvn-hg9gy]

Hahaha. Stay tuned. XD

[@bradorndoff4180]

this helped me out a lot! I'm working on my pilot circuit on my yamaha radian, thanks for the informative video!

[@ltbordo]

your video is the most accurate , informative and concise I've ever found!!!

[@OakstreaMC]

This was one of the best vids I've seen in the carb section. Very helpful.

[@anteradosevic100]

Great job,people like you should have more publicity

[@lindarobinson6588]

Nice job. Very well explained. Educational videos. Was so glad that parts 1 & 2 were back to back. Keep up the great work

[@lprince3884]

Your videos are always on the spot.

[@woodsman7284]

Thank you for this video and explaining this in depth. I have a 08 kawasaki teryx with the 750 and I don’t think the carbs have ever been set right for the riding terrain here in Oregon. So again thank you for taking the time to help

[@Mikefngarage]

great job thanks for making this. seems like whenever I need to do it I forget all this stuff.

[@spike60735]

Thank you very much for sharing that video, it was really informative and you helped me learn how to tune my pilot screws for my Kawasaki KLE500!

[@akbarhussain1767]

Hi there Matthew,thank you so much for your qualified videos & for sharing your knowledge with us ,thank you friend 🙂🙂🙂

[@sonorangaming449]

Watched tons of videos trying to figure out what i need to be looking for, for my carb and no one has explained it as clearly as you do. It all suddenly made sense.

[@jamie.miller.inspiring]

Absolutely fantastic video with the perfect amount of explanation to fully comprehend it!

[@4kiru]

Even 4 years old this video is a god send thank you!

[@richarrrdj]

Great temporary fuel tank....safety is important. great video...will try various adjusts on my kz 750. thank you for video

[@lplp8394]

Really want to thank you for all your very informative video's, I recently bought an 82 XS 650, and since then I have learned how to make noise out of money!

[@trentdumont9576]

Probable the best I’ve ever seen someone explain this most people just set their screws to oem and leave it at that

[@garycook5125]

Very good and helpful information. The popping noise you spoke about, is ignition noise (picked up by camera's audio input), from the motorcycle when running.

[@Rebaldoz]

thanks man .. exactly the explanation that i was looking for

[@kennorway9690]

pff man I don't know what to say, you're the GOAT! it helped so much, thx!

[@heinz-dietersindhoff7344]

You obviously know what it’s about helped me a lot thanks a lot

[@DimaDesu]

Well explained and demonstrated. Appreciate it! Thanks!

[@fredlewis4432]

Thanks Matthew Very interesting Video

[@terp6097]

Nice explanation, learned a few things thanks!

[@SY1WEK]

Thanks for sharing, great video!

[@smcr4698]

Keep up the good job! Well done!!👍

[@17Triumph675R]

I have Mikuni VM26SS carbs and they have both fuel and air screws Just thought I'd point that out to ya but great info u always give and keep up the good work 👍

[@austinado16]

I'm impressed with your knowledge and ability to teach. Taking the time to illustrate the theory is top notch stuff. I learned a lot, and really appreciate the time and effort you put into creating this video. I have an '86 Ninja ZX600R, purchased in '90, and it's always suffered from being too lean in the pilot circuit, and falling on it's face when the throttle is rolled on. I've had the carbs off and apart for cleaning, probably 3 times since purchase, (learning more as I go along in life) mostly due to leaving it sit unused for long enough that the fuel went bad in the carbs, but I didn't know about how jet sizing has an effect on mixture ratio, even though the pilot screw might be out enough that they idle is good. I've even synched them, and although there was a noticeable improvement, it's never be perfect. I'll be I could go a size or 2 up, and cure the issue, if any company is making jets still. Thanks again!

[@HTMR]

Check out jetsrus.com

[@sonnyguacena9807]

Very informative, thank you!

[@howardswift6968]

Finally , someone explains clearly . Very helpful. Thanks

[@Starcore-Studio]

Great explanation, much appreciated...

[@MrLogen]

Best video about those screws :D Thank you

[@AdamDemel]

Two-stroke pilot valve plug

[@rn.85]

Very informative! This is going to save me a bunch of headaches.

[@wickedwickedbar5930]

this is the best vid in you tube no trash just to the point great explain

[@HTMR]

Thanks!

[@snapon454gaming6]

I have a 1980 yamaha xs1100 special and I have been having issues with setting my idle after rebuilding the carbs. this whole video gave me sooooo much help in understanding how this system works, I thought I had an air screw, turns out its a fuel screw. I'm an automotive tech and never messed with bikes before now and I appreciate how in depth you got explaining this.

[@snapon454gaming6]

I just wanted to post an update. Because of your video i now have a running and riding bike. Thank you soooooo so much

[@CCitis]

What did you do? I have a 80 XS Standard...

[@davidwilson8010]

Hey man thanks a lot man I have Ben putting back a Yamaha 2006 r6 for 3 years now..it was throttling good and reving good..I had replace some head o rings n start the bike n it stop reving and a wile after it start to missing n he other thing as well the throttle body get tight..I take the plugs our clean them n free up the throttle body as well n check all wiers n all is good knick ..thanks a lot man n I'll try the 3 turns out n see what..keep what you do best by Charing your nalage..👍💯🔐

[@powerofone1645]

Excellent info man. You rock.

[@HannahFortalezza]

Thank you! This was very well explained and helped me to set up my carbs which wouldn’t idle after a rebuild (where another person said to set them at 2.5, but that wasn’t right for where I live / what the carbs are set like here)

[@harrycalibra]

Just stumbled on you channel oh boy you just have answered a annoying problem with my 1990 ZXR750H2 (uk) my idle is slow to return to normal I do have mods I'm running micron headers to a SP stubby can with K&N filter im running 130 main jets high speed running is spot on. I do sometimes have a problem with the bike cutting out when hot at traffic lights your explanation of the pilot jets which I have set at manufacturing setting one and three quarters turned out looks like I need to turn them out further looks like mine is running lean and the fuel is evaporating before its pulled into the engine . I have uploaded a video of my bike to my channel me revving it and you can plainly hear the rpm slowly returning back to normal idle. Great video your never to old to learn thankyou so much for this video. Happy New Year and I hope 2021 is a good one 😎👍 ps you have a new sub

[@hlrembe62]

I was a tech in a Yamaha dealership back in the eighties and Yamaha said we had to adjust all carbs while using an e-gas analyzer to spec, always too lean, and replace the plugs or they might void warranty. Honda wanted us to do idle drop adjusting which honestly worked much better and no expensive, delicate equipment needed

[@Muchteba]

My bike doesn’t seem to have powerband or the full power it has it kind of feels like too much air or something but before it would bog and just cut off but the bike is a 2022 yz85 and I’m confused it went from fresh to not I cleaned the jets and I tried to mess with the floats and even then out with the top of the carb and cleaned the air filter and changed the spark plug if I don’t know what to do I’m sure it has to do with the carburetor

[@firebird14420]

Why would the pilot screws have to be a 1/2-1 turns out? Both are the same and it just revs higher as I turn screw in, it doesn't bog down till I turn it out around 1/2-2+.. please help me when you can. Thanks!

[@DarkMatter946]

Hanes manual says the same thing for Kawi

[@harisyoung4110]

​@@Muchteba if no powerband try check your powervalve, it could be stuck with too much carbon buildup..after riding at wide open throttle for about 10-20 second, immediately stop the engine and remove the sparkplug to inspect the colour to see whether its too rich or lean..

[@tammyrampersad921]

Got a bran new carburetor and it boggs out got a 1991 4x4 kawasaki bayou 300 4x4

[@jordanblair5410]

Great video, very comprehensive. After removing the welch plugs on my '94 Kaw Voyager 1200, I discovered that two of the pilot screws were buried (zero turns out) and two were about 1.5 turns out. The plugs looked factory, so it's shocking that Kaw (or Keihin) would have messed up so badly. The guy I bought the bike from told me that it was originally sold in CA, so maybe that has something to do with it.

[@tvdinner325]

Very useful info. Thanks.

[@jamesrathbun2482]

How cool is THAT?? I'm working on the exact bike! Thanks for the video.

[@reefkeeperspencer4046]

Thanks for your time

[@chey8869]

Thank you so much for this educational video. I have an 82 Maxim xj1100 and have been going crazy as to why it wasn't idling without a full choke. Can't wait to try this!!

[@itruns]

It's lean if it won't run unless you are fully choked. Choke decreases O²

[@MT_T991]

​@@itrunsthough often you see enrichers not chokes.

[@dandavidson9030]

Great Carb info

[@quadflopper1012]

thank you, this is the closest any video has gotten to providing any information that I can relate to the hitachi hsc32 carbs on the 1980 yamaha xj650 i recently acquired, in fact the carbs are out laying on my bed from me just getting through 2 hours ago putting them back together again for the 5th or 6th time. there is no information in the manual for the fuel adjusting screw it just says "preset (no datum given)" so now I have a guide line to work from, thank you again......

[@HTMR]

No problem!

[@brewer7604]

Thanks excellent video

[@Siper2]

Excellent tutorial, thank you! Currently working on tuning the carbs I just rebuilt on a 1994 Yamaha XJ600. My first time doing it, so it's a minor miracle that they don't leak. 🤣 Idles fine but acceleration is poor. I have a MotionPro sync tool I'll be using, and this method to work on the pilot screws. A wideband O2 sensor was a good method suggested, but pricey and involves welding. This looks much more doable for me. I stepped my OEM pilot jets up from #17 to #20. Main jets are stock. We'll see how it goes!

[@HTMR]

Good luck!

[@eriknilsson1903]

very good explanation thanks👍🌟

[@danatompkins5847]

Thanks man, great explanation on how it all works. I recently resurrected an 86 vmax that had sat for 10 years, bad gas, rusted tank, frozen carbs, etc. Runs great at upper rpm but won’t idle without choke. I should have removed the factory set pilot screws before I soaked the carbs, as you mentioned, probably the issue. Going to do it now. My thinking, since only has 5k miles, was that factory setting probably correct. I might even see about getting larger main jets, but the thing is insanely fast the way it is.

[@HTMR]

Yeah you need to remove the fuel screw and clean the passage. It is the most important and smallest one.

[@rogertully9064]

Nice when someone is willing to share knowledge, good vidio very well explained top team player.

[@benlafrance]

Awesome video thanks

[@stanmorton8975]

Great explanation on afr.....thx

[@carlosecheverria1401]

Great video..

[@peterkroeker753]

Thank you a million!

[@jameswoenker2659]

Just bought a79 Honda 650 cb. Fun stuff.

[@notandylincoln]

That's the same one i've got. Gotta retune the carbs for the summer. How're you liking it?

[@1conu593]

I also use spark plug color as indicator, trying to aim to a brownish color. Starting from being too rich with carbon black spark plugs making adjustments down and always running the bike for at least 30 minutes, with highway parts and check again color until right. It can take several days but it seems the most precise method without the use of fancy tools, what do you think ?

[@tranphucthanh5178]

Thank you, you are the best

[@krupp27]

Hé Nice video im going to try to tune my kle 500 this saturday with your video. Greets from the Hellevoetsluis Netherlands

[@krupp27]

@Animal Mother haha i brought it away for ultrasonic cleaning to an motorcycle shop and they cleaned it en adjusted it for 50 euro 😃 so I never did it 😑😁

[@michaelmilton8925]

Individual filters are great maintenance wise. Had em. Bad in the rain though bike runs rough.

[@garethlipyeart6520]

excellent vid great help.could gauges I guess to get the fastest idle,on my old tiumph trident I went from 17 to 19 pilot jets and was surprised on the performance gain as I always thought pilots only really did anything at tiny throttle openings it also got rid off the tiny stumbles it had in traffic,this vid is more applicable to a gs1000g I may be buying but great stuff well done

[@HTMR]

Thanks!

[@steenhansen6428]

Great turorial.👍👍👍🏍🤟🏻

[@nbiggs]

Absolute clinic. Insta-sub. Thank you 🫡

[@Dosalt]

I always ran lean because it gets great efficiency and economy. That extra power gain you get from running rich is not important unless I go to track. When I do track I retune it to slightly rich. Good video.

[@HTMR]

Sure. I go for performance, sacrificing fuel economy.

[@danburque7555]

I'm going to 3 turns air screw instead of 2 and 1size richer pilot jet. I've had a low speed cruise sneeze for years bugging me. THANKS 👍

[@ronhanish]

good stuff!

[@poopslappen]

Thank you

[@joakimberggrenandersen9953]

Tack!

[@ian7583]

Nice job bud 👍

[@mistermacgray]

My problem is I have new mikuni rs36-d8-k carbs on my yamaha xj1100 amd jetted for the engine and per directions it says to turn them out ⅛ to ½ turns out max but it doesn't say from a light seat, fron a turn out, or anything in the directions. A light seat is something that is hard to determine because it is seated against a oring and each carb has a different feel and look when you look at each pilot jet screw with the carbs off so I've ordered a colortune to see where thigs are at. Your video is a great watch for sure and explains things perfectly.

[@nohandle5544]

Wow excellent Matthew, I have been mechanic on these for 55 years but some mixture screws didn't give me the proper response..you have taught me how to better decide the pilot jet configurations..Who says you cant teach an old dog new tricks..lol Oh by the way..the carbs are already synchronized before this video?..Yes? Liked and subscribed..thank you very much. Peter

[@HTMR]

Yes carbs need to be synched before this procedure.

[@merrilldoyle8300]

Hey Matthew! Great videos you are truly a professional. I have a problem with ground issues. When I start my bike with jumper cables and remove the ground clamp i get a really good set of sparks. I have pulled the stator. voltage regulator it all seem to check out. Is something wrong! Build bikes for everyone. Merrill

[@skidivr]

This info applies to the carbs on small airplanes. same principle on the idle. thanks.

[@HTMR]

Pretty much same principle for all gas engines.

[@n.o.b.s.8458]

Just tuned up my pc800 and added a new air filter. 65k miles and she's running like a peach!

[@mor2bz]

did you saw off he stops on the air/fuel limiters/?

[@RogerDiotte]

Oh, " and I also just made this number up" lol....regardless...I just took some of your advice! Very nicely done btw! I've ordered two Main jets size 125 , two Pilot jets size 42 and 2 shim for each Slide Needle for my 84 750 Shadow!

[@shammon1]

super clip thanks

[@JimAppleby]

Thanks!

[@HTMR]

Your welcome

[@thejunkman]

This is a good video. I hope between both your videos and mine, maybe people might start to understand how to do this on their own. But still I think people don't want to spend the type testing, changing a setting, testing, and so forth.

[@HTMR]

Thanks. Tuning can be a PITA, however with this circuit the answer is in the screw setting. Don't even have to ride it to determine if it is lean/rich.

[@thejunkman]

Right, but novices I think lack the analytical mind we may have. This video builds on our previous information around the topic. Too bad it can't be better centralized. I have tried to do that on my website, and I might embed your video there.

[@HTMR]

@@thejunkman Yes and this is also assuming the carbs are in perfect shape. We all know that is rarely the case.

[@ItalianMetalHED]

@@HTMR my vtx mixture screw was completely burned out and crudded up with rust and kept playing with the mixture not realizing till I dug deeper and once I cleaned it up it was much more responsive but now I’m dealing with slight hesitation during acceleration using barons set with 210 but they didn’t assign numeric value on pilot

[@kaly652]

Thanks

[@craigroy1044]

Hey, just a great explanation and I love rule of thumbs!! Can you tell me where can I get mukuni jets?

[@yogiatpozen]

This popping sound is your microphone picking up ignition coils/spark plugs running

[@darshmaheshpatel7291]

Great video, clears my concept, I need help, sir. I have a 1986 Yamaha YX600 Radian. I am cleaning my bike's carb and I messed up with the pilot screw turns. Initially, before opening my carb I adjusted the screw which operates the throttle position. Now when I adjust the pilot screw how to combine the tuning with the throttle position screw? how does it work together? and which one should I adjust/tune first? Pilot Screw or throttle position screw?

[@SixWheelsDown]

my 90 gs500e's stock spec is 3 turns out. When on the highway at speed, if I slowly roll of the throttle and then back on again (to go +/- highway speed) it pops as I turn the throttle. Doesn't pop anymore after the throttle is turned 1/8. These are set to run lean for sure, so my thinking is 3.5 turns out, which is what I had it at prior to resetting it. this video is awesome. greetings from Chicago!

[@HTMR]

You are marginal on those pilot jets. Probably need to go up 1-2 sizes.

[@SixWheelsDown]

I probably do. Maybe ill get some new jets. You should also mention in your video that most of these non-oem jet kits come with inferior brass jets. that was a problem I had with the rebuild kit I got from ebay. i ended up not using them all. but the float bowl gaskets were good!

[@SixWheelsDown]

on the Mikuni BST33's that the GS's come with, the thinking is 3.5 turns out is the most you can do anyway, so if this doesn't solve the problem, new jets will be the answer. Why am i throwing parts at a 29 year old bike?? Because it had 10,500 miles on it when I bought it.

[@severelifestyle1]

Great video. Very helpful

[@bobbrown8615]

Well. . .I have looked and looked and this is so helpful, beats everything I've seen, so very well done and much appreciated. I could use a few minutes of private tutoring, are you available?

[@gixxerfixer1358]

I need a friend like this guy, I go to mechanics and they mess my bike up more then when I brought it, where's all the good semaritan mechanics in NY

[@russellsitaro8505]

I finally took the bike to a mechanic and had him do the valves and sync the carbs. Bike runs like new

[@russellsitaro8505]

I’m pretty sure that I could have done the valves myself and got it running sweet but it was well worth the money spent for piece of mind that it was done right. In fact the guy that did the work rides a Radian also. He said he was jealous at how nice my bike ran. I guess I got a good one.

[@Pinchegalloo]

How much did you soend

[@JohnSmith-yn8pl]

I did not read here where anyone talked about checking actual air flow on each carburetor. I used a device that had a rubber seal. Place the device on carburetor # 1. There was a ball that floated in a clear tube. Adjust it until the ball floats in marked center. The place the device on # 2 carb. If the ball was not centered, you got to adjust carburetor linkage to sync the carburetors. Same with the #3 carburetor. You need the exact air flow on all carburetors. Last adjust the mixture needles. The only way to get it done right.😅

[@dallaswhyte1748]

Have you done a carb adjustment on a 1978 Suzuki gs1000? Would help greatly. Thanks.

[@oeeoeoeoeoeooeoeoeoe]

Hello! Thanks for the detailed explanation! We are also in the the process of the tuning the fuel screws. Two questions if someone knows to help out 🙏 1. Before starting the process, where should be the idle revs configured? High, low or manufacturer suggested? Or something else? 2. What happens if the screws are in a location where it is probably impossible to tune them while the engine is running. Any tips and tricks? P.S. The bike we are trying to tune is Honda Cbf 600, 2004. Thanks!

[@12dbrhdwk61]

Very useful video. i think fuel screws should be adjust first and carbs syn`c next.

[@HTMR]

I like to get fuel screws close, then synch, then final fuel screw adjust.

[@jluis5188]

BEST VIDEO ON KZbin! QUESTIONS: I backed my idle screw all the way out on my vtwin 1100 vstar, and it still idles at around 800 RPM. When I lean it out idle goes down and when I richen it the idle goes up. But where it idles smooth and fast is too fast for the lowest idle screw setting. Also, note that when I close the AF screw all the way the bike still idles and will not stall even with the AF screw all the way in on the front cylinder. Also not that the rear cylinder AF screw has no real effect to any change I make to it, except the backfire pops, when I lean it out and less backfire pops when I richen it, but it does not have any real effect at idle. Only the front carb seems to affect idle. I bought this bike second hand. I think its time to ditch the carbs and buy another used set and start over?

[@HTMR]

Probably best to take the carbs apart and clean them. I have a video on that here: www.howtomotorcyclerepair.com/hondashadowcarbclean/

[@xtremesounds4117]

Our V-Star doing the same

[@xtremesounds4117]

Trying to see why it smells so rich and my tailpipe is burning cherry red hot after 10 mins