Yz250f jetting guide Yamaha lightened up the hub, sprocket, chain and they installed a 2. The general tuning principles provided will apply to all two Hi,I got a 2012 yz250f that I need some help jetting I’m running a 185 main and I think a 45 pilot jet around 900ft election and around 2-2. We did this with our RM125. For the best results, stick with fresh, high-quality fuel to ensure consistent combustion and optimal throttle response. I have a 2001 YZ250, with the stock jets and slide and no mods to the carb. lots of differencesso i will condense the majority of the thread to info pertinent to my all time favorite 4-stroke carb the KEIHIN FCR carb. Our year, make, and model fitment guides list jets for popular factory and aftermarket carbs, but due to numerous reasons there is not a way to make them 100% accurate. A 125 Keihin jet This is a comprehensive look at the Keihin PWK. I need some carb advice. Added and adjusted fuel screw, installed accell pump cover no change. JD Jetting Kit Can anybody fill me in on what the JD Jetting kit is, and why somebody would want or need it? I have a 2002 YZ250 I use mostly for woods and desert riding. Oct 14, 2019 · Hi guys, had my 2016 Yamaha YZ250 for a while now, but not ridden it since mid winter now. View and Download Yamaha YZ250X 2022 owner's service manual online. You can order the needle for $10 off Rocky Mountain. . com, world leader in Carb Jet Kits. This is my 1st 4 stroke and am wondering what t Apr 14, 2014 · As with every jetting guide, there are caveats about temperature, altitude, riding style, hop-ups and personal taste. 95 Add to cart JDY006 – Yamaha YZ450F (06-09)/ WR450F (07-11) $ 84. " Randy Mar 10, 2013 · there are lots and lots of carburetors out there. The Cyclepedia. The recommendations in these instructions are based on use with our billet cylinder heads, however every bike, combination of mods, and location is different and additional tuning may be required. The target weight we used for this suspension setting was a range from 150-170 pounds. We also wanted to give you Tuning Tips & Manual Downloads Please Note: Other than exact replacement OEM carburetors, all Mikuni Aftermarket Carburetors and Tuning Components are sold “As Is” for Off Road / Racing Use Only and are not intended or approved for use on vehicles operated on Public Roads or in Locations where applicable engine tampering and anti-pollution laws apply. Shiny Red Tuning is a 2-stroke scooter tuner and Gilera Runner specialist with in-house dyno facilities and a fully equipped machine workshop. Jul 25, 2010 · The JD jetting kit is excellent, here are a few threads that you should read and most importantly understand Two stroke YZ jetting guide spankys jetting guide The JD jetting kit offers a jetting needle that is specifically tapered to your bikes engine based on year. When it comes down to it, the taper of the needle is the biggest deciding factor of how a bike runs and jetting is super important on a two stroke. These are recommendations only, based upon our testing at sea-level atmospheric pressure, a 65-80F degree ambient air temperature, a 32:1 fuel to oil mixing ratio Yamaha's ground-breaking Power Tuner App is extensively updated for the new YZ450F and YZ250F - and better than ever — more functionality, a wider range of adjustment, improved interface, and now even easier to use. Half a century of YZ development. Probably a good place to start. Thanks, great! :tup: This is a pretty basic outline for jetting on the YFZ450. I am looking to see if anyone has any jetting info for high elevations. Below the instructions here are the needle and needle jet info that you will need to know such as the inner diameter of the needle jet of your carb. At 6500-7000 ft, it will bump start, but mak Jun 20, 2013 · This is the 2010 Yamaha YZ250F the way the MXA test crew raced it. Yamaha YZ125 Jetting + 30 Pro Setup Tips & Discount Codes to Save Money & Go Fast! Ryder Sigety 4. With fine tune adjustability and multiple inputs, the Power Commander 6 will keep your vehicle running at its full potential letting you concentrate on the journey ahead. How do i know what size jetting to buy? And is there a carburator tuning guide that anybody knows about???? Posted The Keihin power jet & throttle position sensor on the YZ250 & YZ125. This does not provide all the answers to all carburetor issues. In 1974 I bought my first YZ250A, an insanely pipey and lightweight bike with 4 inches of suspension travel and a powerband like a Cobra 50! Ever since 1974 I’ve focused my attention on making YZ250s the best 250. Any ideas? Also bike bogs under heavy load and wants to die. Carburetors are jetted using stock motorcycles and watercrafts. Almost gave Oct 20, 2020 · Hi guys Just bought a full pro circuit exhaust system for my yz250 2020, just wanted to getting people thought on jetting with new exhaust I have heard you should go to a 180 main ? Cheers just wondering if the JD jetting kit is a good choice for a sickly 06 WR250F. The PC pipe/silencer has increased pulling power out of corners (mid-range) and just feels like it’s more torquey. Please remember that sometimes the stock OEM jetting will work just fine, other times you may have to make an adjustment, so use our suggestions below as a guide to help with your jetting problem. What Does Jetting A Dirt Bike Mean? Jetting a dirt bike is just changing the size of jets and adjusting the needle to change the air to fuel ratio (AFR). Keihin, Mikuni and Aftermarket jet kits use different numbers to indicate jet orifice size. See my complete 4 stroke jetting guide here. I will try to add more pictures as time allows, but this is a start. 1 mega bomb pipe ported the head jd jet kit twin air filter and removed the screen airforce moto tassinari air boot currently running a mix of aviation fuel (100LL) and premium 3 gals avgas to 1 gal premium jetting current Jul 9, 2025 · Yamaha’s YZ250 two-stroke motocrosser remains a core favorite, and a venerated icon of the past with a modern lightweight chassis and simple yet potent engine. how many of you guys have JD's jetting guide. Sep 12, 2003 · Our very own "edge" has compiled this great little jetting guide for all of you who are having problems, or need a starting point before you attempt to re-jet your YFZ450's FCR carburettor. What jets should I put in there? If it matters, I live at about 4500 feet and the only performance mod I know of is a slip on Dr. Until, I found your jetting guide! Now the bike starts first kick without prime-kicking and has almost zero bog/sputter. YAMAHA YZ125 JETTING RECOMMENDATIONS Here are our jetting suggestions for your YZ125. Certain parameters may vary due to air pressure and temperature, altitude, umidity. A correct AFR will yield the most power, efficiently, reliability, and run the cleanest. Any help would be appreciated 🙏 Jun 8, 2010 · If everything continues to go smoothly I’ll be picking up a ‘24 Yz 250x at the dealer tomorrow. Also read that people have been moving more towards yz250 jetting standards to get this thing right. The author cannot be responsible for your Nov 6, 2023 · Rebound: 10 clicks out 2024 Yamaha YZ250F: The 2024 valving is a little beefier but the spring rates remain the same on the new YZ250F. 95 Add to cart JDY005 – Yamaha YZ125 (01-21)/YZ125X (20-22) $ 84. These are recommendations only, based upon our testing at sea-level atmospheric pressure, a 65-80F degree ambient air temperature, a 32:1 fuel to oil mixing ratio Jan 29, 2018 · You'll probably write off this advice but I had a 2007 YZ and I went to a NECJ needle and it was worlds better, much cleaner running and revving. We have 1 Yamaha yz250f 2012 manual available for free PDF download: Owner's Service Manual Dec 11, 2024 · If you have never jetted your bike correctly, you will almost certainly gain some performance at some point in the bike's power-band. Mar 8, 2009 · INSIDE THE MXA TEST OF THE 2009 YZ250F In last year's test of the 2008 Yamaha YZ250F, the MXA wrecking crew stated that we thought the YZ250F was getting outdated in comparison to its newer and The Cyclepedia Press LLC Yamaha YZ250F printed service guide features 338 pages of detailed black and white photographs and wiring diagrams, complete specifications with step-by-step procedures performed and written by a veteran Yamaha dealer trained technician. Keep an eye on the plug as a guide, but I've found from testing with a mate on his YZ250 that these bikes aren't too finicky and work well across a variety of conditions with 1 setting. 5, or 130 as the NEXT larger jet size. At the same time I want to look at getting my jetting in the rough ball park for the summer over here in the UK. If you shop online at Rocky Mountain ATV/MC please click this affiliate Jun 13, 2014 · Need more jetting advice? Alright, this post tackles one circuit of your carburetor only. To me the Twin Air YZ250F PowerFlow kit is the best all-around filter system for the YZ250F airbox. Its mysterious but it doesn't have to be. This large hole is accessed via a 17mm Hex drain Mar 3, 2021 · Stock jetting on the YZ's is good, so start there. YAMAHA YZ250 JETTING RECOMMENDATIONS Here are our jetting suggestions for your YZ250. The top end signs Written by yamadmin . Introducing the new 2026 Yamaha YZ250… On the track or on the trail, the YZ250’s exhilarating 250cc liquid-cooled engine provides an instant hit of power for holeshot-winning acceleration. For two-stroke bikes, our jetting specs are for VP Racing C12 Racing All Keihin carburetors are pre-jetted for bolt-on operation. 95 Add to cart JDY002 – Yamaha YFZ 450 ATV (04-08) $ 84. As a rule, we don?t go for exotic or expensive mods, but if push comes to shove, we will seek competent help (no matter how much Please keep in mind, this is a generalized guide to tuning and jetting a Mikuni round-slide carburetor. This example is from a YZ250, but the design is very similar to all modern Keihin PWK carburetors. The screw adjusts how much air is allowed through the pilot jet. In the tuning section I wanted to put in a suspension and a jetting section. com Yamaha YZ250F online service guide features detailed full-color photographs and wiring diagrams, complete specifications with step-by-step procedures performed and written by a veteran Yamaha dealer trained technician. If the jet in the carb does not dimensionally measure like ours, then it is not correct. Tips This is the base guideline about tuning your Keihin. Valve adjustment I just want to mention that tight valves may also cause hot start problems. And does temperature effect the jetting? If so, how much? Thanks for yo Sep 25, 2021 · The 2022 Yamaha YZ250F doesn’t have the changes on paper that you would like, but the bLU cRU did do some minor updates to help try and lighten the YZ250F up some. Jetting Specifications We have developed a list of jetting specifications that we believe will help your bike run its very best. Jan 17, 2011 · I have been overwhelmed with questions asking for pictures of how to rejet, or the locations of jets. Manual gives no clear indication of which way jetting needs to go. Comments Has this post/video helped you? Please comment below. Sep 25, 2021 · The 2022 Yamaha YZ250F doesn’t have the changes on paper that you would like, but the bLU cRU did do some minor updates to help try and lighten the YZ250F up some. The Yamaha YZ250 F online manual covers: 2006 Yamaha YZ250FV Four-Stroke 2007 Yamaha YZ250FW Four-Stroke 2008 Yamaha YZ250FX Four-Stroke 2009 Yamaha YZ250FY Download the 2012 Yamaha YZ250F Owner's Manual PDF for free. Do not buy it! It will not work. I'm gonna tear it down today and check mains etc, and order a new piston etc. 15 rear rim (instead of the 1. 1/4 turns out and need some recommendations on what size jets to use James, are you still making your jetting guide available? If so, how do I snag one of those pieces of *Excel wizardry? It's time to chase away the "bog monster. Apr 9, 2013 · Hey guys! I am wondering if anyone can suggest a good setup for a stock late model YZ in the woods? I haven't had any problems riding moto with the stock jetting, but have noticed the bike loading up pretty bad in the woods. com [ August 29, 2002, 09:41 PM: Message edited by: James Dean ] Jul 10, 2025 · What Does The Air Screw Do? The air screw is the "fine-tune" adjustment for the pilot jet (sometimes called the slow jet). This 2 stroke jetting guide will show you how to start getting results in minutes, even if you're new to jetting. Description James Dean designed and perfected this jetting kit over years. 23K subscribers 372 Jul 9, 2025 · Best Bang For Your Buck Mod: Jetting The single best mod for most 2 strokes, including the YZ125, is getting the jetting right. For two-stroke bikes, our jetting specs are for VP Racing C12 Racing May 23, 2008 · Here's a quick reference jetting chart for '01-'08 YZ250's It was made by taking Yamaha's manual recommendations and using the density altitude calculator to correct for altitude and temperature. A 125 main jet may have a 127, 127. It is jetted really well right now for our hot and dry AZ weather and our elevation. 95 Add to cart JDY003 – Yamaha YZ/WR 250F (01-05) $ 84. It is much more forgiving for jetting because it The jet kit includes instructions and charts that carefully walk through the installation process and offer guidance to help get peak performance at all elevations and in all conditions. The suspension is still a little soft in stock trim, so if Feb 20, 2025 · The Power Commander 6 fuel injection tuning device allows you to optimize your fuel and timing curve (where applicable) giving you the confidence to roam freely. 5 (this means that the cutaway is 7/32") Float needle valve: 3. JD Jetting, World Class Motorcycle and Off Road custom carburetor tuning, jet kits, carburetor kits, carburetor needles, jet screws, KTM, Honda, Suzuki, Yamaha May 7, 2014 · I'll start by making a record of the changes i have made to the bike FMF 4. Apr 4, 2018 · Here are things that can fix that problem: 1) A hotter plug 2) Leaner jetting (move the clip upward on the needle jet and / or get a smaller main jet) 3) Less oil in the gas (higher ratio). These will not make you an expert tuner. WARNING ! This section features the PWK exploded views just to let you understand where the I have a project in my technical journalism class where I am doing a manual titled "Proper care and maintenance of your YZ 250F". When rolling the throttle on you’re able just to feel more meat as you’re able to shift the YZ125 a little sooner. JDY001 – Yamaha YZ426/450F (00-05) WR400/426/450F (00-06) $ 84. Jan 31, 2016 · Ok gurus. Manuals and User Guides for Yamaha yz250f 2012. Learn more Installing a new FMF pipe and silencer along with a JD jetting kit on our 2024 YZ125. Below is a screenshot of my spreadsheet for Keihin carbs (PWK, PJ, PE). The following is a guideline for jetting Keihin carburetors. YZ250X 2022 motorcycle pdf manual download. Mikuni Carburetors should be replaced Jun 19, 2025 · Review – Key Features – Features & Benefits – Specifications 2026 Yamaha YZ250: THRILLING. Apr 6, 2008 · 2008 YZ250F Stock jetting dies on throttle blip. This is a view of the bottom of the carb, looking up towards the top. 95 Add to Jan 4, 2022 · Jetting specifications are identical to the 2021 model for good reason; there’s not much room for improvement. Be carefoul when jetting, a bad jetting can produce huge engine failures. If you followed the above and continue to have hot start issues, check out my YZ250F Valve Adjustment Video. Featuring a plug-and-play setup, Power Commander 6 can be Make: Yamaha Model: YZ65 Relevant Years: 2018 - 2023 Oem Trim / Test notes: Yamaha’s newest addition and well received 65cc capacity racer is a great bike but much like the YZ85, it is missing key internal components to compete against the Ktm group machines. does this kit come with a book or chart explaining which jet is a goo dplace to start so u arent pulling the carb 500 times. This JDJetting kit is purpose-built to improve throttle response throughout the RPM range. It also provides a guide for determining rich or lean car-buretor conditions. Jun 13, 2014 · Need more jetting advice? Alright, this post tackles one circuit of your carburetor only. Perform the jetting in the order given below. Oct 1, 2006 · The manual for that bike has a decent tuning guide in the back that takes into consideration temperatures and elevation. 85 2021 rear rim), as YZ250(X) Jetting Instructions Congratulations on your purchase of an Apex Technical Innovations Cylinder for your Yamaha motorcycle. These settings are for Sep 30, 2023 · What jetting are you running, needle and clip setting. Try here: identify that jet. A pocket-size slide calculator which determines required jetting changes in Mikuni carburetors due to ambient temperature, altitude, or both. I have been messing with clickers as well as Yamaha Power Tuner maps and we’ve decided on the best ones right here. Feb 22, 2022 · Hey everyone, Picking up my YZ125 from the dealer soon. Aug 13, 2007 · Main Jet: 370 Needle Jet: Q-2 Needle: 6DH3 (start in the middle clip and tune from there) Slide: 3. It's the answer to many problems. The carb is obviously running rich, but still starts by the third kick at home. 85 2021 rear rim), as well as went to Mar 11, 2024 · The YZ125 is unchanged for 2024 but since we didn’t give you YZ125 owners any love in 2023 we are here for some suspension and jetting specs. D silencer. We have 1 Yamaha yz250f 2012 manual available for free PDF download: Owner's Service Manual JDY001 – Yamaha YZ426/450F (00-05) WR400/426/450F (00-06) $ 84. Download the 2006 Yamaha YZ250F Owner's Manual PDF for free. I've The Cyclepedia. Yamalube R at 32:1 is probably just fine on that bike. Free Shipping on orders over $50. The Cyclepedia Press LLC, Yamaha YZ250 (2 Stroke) online service manual features detailed full-color photographs and wiring diagrams, complete specifications with step-by-step procedures performed and written by a veteran Yamaha dealer trained technician. May 4, 2017 · There is something new out on jetting! See: www. Instead of these setting being jumbled in general 2022 yz125 posts, I wanted to rea Sep 11, 2003 · I have yet to foul a plug running the JD Jetting settings on my YFZ with a Sparks pipe and the YZ exhaust cam. Proudly made in USA. We recommend that if you are a novice, you consult a professional mechanic or technician for your specific needs. I live in Northern Arizona at 5,700ft and most of my riding will be between that and 8,000ft. 95 Add to cart JDY004 – Yamaha YZ250 (00-25) YZ250X (16-25) $ 84. Dec 13, 2007 · Found this on the web, thought it was basic but to the point: Note: Jet sizes increase in different increments. This is important for jetting to get the proper air-fuel mixture. Worth every penny! I have a 2004 Yamaha yz250f with stock jetting and I spent at least 6 months trying to get rid of the famous "Yama-Bog", swaping jets back and forth, playing with the needle clip position, and messing with the leak jet screw but nothing worked. When i got a no toil intake kit installed the mechanic working on my bike replaced what i think is the piolt jet and said if i had exhaust he would replace the main jet. With mods these bikes like more fuel, so look to increase the main up 1-2 sizes when you add the pipe. It pops a little and bogs a little too. 2021 YAMAHA YZ250 JETTING Main Jet: 178 Pilot Jet: 50 Needle: N3EW Pro Circuit Product, Inc. Don't do it yourself if you don't feel confident but let it to a professional mechanic. 5 Float level: 27mm Slide cutaway measurments explained: Each whole number on a Mikuni Roundlside carb represents 1/16" of cutaway from the bottom of the slide to the top of the cutaway. Nov 18, 2021 · The fine-tuning is still up to you, but YZ250 jetting has stayed the same for years, so it isn’t hard to get dialed in. MXA’s numbers are suggested starting points for motocross racers (the stock MXA WRENCH TECH: YAMAHA YZ250 TWO-STROKE JETTING FROM 1999 TO 2014 Motocross Action Magazine As a rule, we tend to go a tad richer on the main when we hop it up, add a pipe or race in heavy loam Description James Dean designed this jetting kit for Yamaha riders looking to push their motorcycles to the next level. The kit comes with instructions and charts that carefully walk through the installation process and offer guidance to help get peak performance at all elevations and in all conditions. Any major engine modifications like higher compression pistons and racing exhaust systems may require minor jetting adjustments. The Yamaha YZ250 two-stroke online manual covers: 2005 Yamaha YZ250T 2006 Yamaha YZ250V 2007 Yamaha YZ250W 2008 Yamaha YZ250X 2009 Yamaha 5 days ago · Shop online Jet Kit for 2010-2011 Yamaha YZ250F @ Dynojet. The jet kit includes instructions and charts that carefully walk through the installation process and offer guidance to help get peak performance at all elevations and in all conditions. Explore the manual online, or choose to print or download it on your computer. These are recommendations only, based upon our testing at sea-level atmospheric pressure, a 65-80F degree ambient air temperature, a 32:1 fuel to oil mixing ratio Aug 25, 2023 · After spending more than 2 weeks adjusting the carburetor jetting on my new 2023 YZ125 I have finally found an ideal setting and want to share it with you. I live at 5000 ft and ride from 3000-7000ft most of the time. We have developed a list of jetting specifications that we believe will help your bike run its very best. Mar 29, 2020 · The Pro Circuit Works Pipe and R-304 silencer has a deeper sound than the FMF/stock system and gives the YZ125 more bottom end than the FMF. I'd be wary of this one, as little engines tend to like more oil. If you want to get rid of the somewhat janky stock air filter cage system of the YZ250F, go with the Twin Air Power Flow Filter Kit. Also all the pipes out for the YFZ are going to be pretty close to the same jetting-wise so this FAQ should get you pretty close. I'm a 800 above sea level and can't get my 2024 yz125x to accelerate properly. Here's how to use it: Enter data into all the light blue cells James Dean purpose-built this jetting kit for riders looking to improve running performance and throttle response throughout the RPM range. YAMAHA YZ250F Instructions for ordering: check jet dimensions. Lets dig in and see how it works, how to test Sep 26, 2021 · 5. Also for: Yz250xn 2022. This is the Jetting Keihin carburetors Click here for my page verifying the jetting calculator for Keihin PWK/ PJ/ PE carbs. JDJetting. I broke the main jet inside the carb while trying to swap them out. We are really hoping this will solve are jetting problem with this bike. Posted in How To Articles Quick Jetting Guide for Mikuni and Keihin CV (carburetors with movable jet needles) The following tips and insights are for your information only. Our setup kit for this bike addresses these key issues. Therefore, do Sep 9, 2016 · So I bought a 2007 yz250f, and it runs rich. With the stiffer chassis for 2024, it’s tougher to dial in the KYB suspension but after a long time spent on the new YZ250F we think we have found a comfortable spot for you all to start from. I’ve read everywhere that it’s jetted rich from factory. Each kit is different, it really takes the hair pulling out of choosing a needle. Here are some basics for you on how to jet your 2-stroke. You can easily gain torque, horsepower and throttle response in minutes, even if your bike seems to be running well. Why? Oct 23, 2024 · The Yamaha YZ250 is 50 years old now. I know I have read a more in depth suspension guide than what is provided by the Yamaha Manual. JD Jetting kit vs DIY Do you want to Jul 9, 2025 · This post will review all the aspects of installing a big bore cylinder kit on your 2001-2013 Yamaha YZ250F or WR250F and 2014+ models, including what it takes to install it and the jetting changes required. We’ve spent countless hours of testing to determine which settings work best when bolting on one of our pipes and silencers to a stock machine. From a hot summer day in California to a cool winter evening in the dez, the Yamaha didn’t give me jetting fits. Apr 5, 2024 · Had a comment request to make a video of 'jetting the 2 stroke', here it is. Pro Circuit Product, Inc. Live in florida so im at sea level with a lot of humid weather. Shop now & Save big! Sep 3, 2024 · The 2025 Yamaha doesn’t have a ton of changes on paper but the changes that it does have seem significant enough to feel on the track. The kit comes with instructions and charts that carefully walk through the installation process and offer guidance to help get peak performance at all elevations and in all conditions Shop official FMF Racing dirt bike & ATV mufflers and exhaust parts, exclusive apparel, t-shirts, hats, goggles, and sunglasses here. keihin is a subsidiary of Honda Motor Corp and their 2-stroke and 4-stroke carbs are state Lower-quality or low-octane fuel can cause tuning issues, poor performance, and starting problems—not just with our carburetors, but with any carb system. cns thhh rqzul gobhno livnj guor nvw mfkzn kbneozf ravcglg zxeno galwp jyytauv vdgf pyhog