SmartCarb For Yamaha YZ250
$674.10 – $853.20
Wake your YZ up!
This 38mm SC2 model SmartCarb replaces the stock carburetor in Yamaha YZ250 dirt bikes, offering holeshot-winning performance, corner-ripping torque, and tool-free tuning.
MagVolt® Throttle Position Sensor option recommended for bikes equipped from the factory with TPS for 3D ignition mapping (2001+). Click or swipe through the photos to view the Type 1 and Type 8 connectors. Select the type that matches the connector type attached to your stock carburetor.
Every SmartCarb ships pre-adjusted specifically for the bike for which it is ordered. Please provide information in the forms below about any engine/exhaust modifications, how you ride (riding style), and what fuel selection and oil premix ratio you use.
Questions about compatibility, sizing, or fitment? Contact Us!
Products shipping internationally may be subject to import duties/taxes.
Description
This SC2 SmartCarb replaces the stock Yamaha YZ250 carburetor. It is a precision metering instrument that provides extremely fine fuel atomization, precise mixture control, and air density compensation in a single circuit, jet-less fuel system.
- CNC billet aluminum construction
- Patented single fuel circuit design
- Extremely fine fuel atomization
- Optimal air/fuel ratio control
- Designed & manufactured in the USA
Learn more about How It Works
Rof Rimot –
I installed a 38mm SC2 Smartcarb on my 2006 YZ250 along with an APEX enduro head. WOW what an incredible difference the carb and head mod made. The low end torque is amazing, mid range powerband very strong and the full hit of the powerband is just as strong or stronger then the factory set up. I spent countless hours pulling the factory carb jetting and testing. No matter what I did I could not get the factory carb dialed in 100%. The Smartcarb is plug and play. I installed the carb and have never changed anything after. YZ always starts first kick and runs crisp. I also noticed my fuel economy is better with the Smartcarb and I have not fouled a plug in 40 hours of use. I’m buying a new 2025 Sherco 300 and will be installing a Smartcarb SC2 on the Sherco. The tech support at Smartcarb is first class. Fast response and always willing to help. I highly recommend Smartcarb.
Alex Leadbetter –
I love the SC2 as I know no matter what the temperature or altitude may be my bike will be running perfectly! I can lug at low revs over slippery tree roots and wring it out with huge over rev in the fields. I’ve raced with SmartCarb since 2018, and I can’t see myself ever racing without them in my corner.
Tom Raio –
I recently installed this on my 2017 YZ300x, and right out of the box, it performed flawlessly. Having previously installed an Athena 300 kit on my 250x, I was looking for a carburetor that required minimal adjustments and delivered consistent performance across various conditions. This product exceeded my expectations.
While the stock carburetor functioned, it often felt sluggish and became finicky with the jets after the 300 kit installation. My bike primarily handles harescrambles and enduros, with the occasional Moto session. With this carburetor, I noticed a significant improvement in fuel efficiency, a clear power increase, and an impressive ability to lug the bike effortlessly.
When I put the bike in a tall gear and held it wide open, it ran smoothly throughout the entire RPM range. Moving forward, I wouldn’t hesitate to install an SC2 on any carbureted bike.
Jason Schwarz (verified owner) –
If you’re like me jetting as a weekend warrior I don’t have the time for. I want to get on the bike, rip, and enjoy it. This does that. Honestly I spent quite a bit of time reserching between Lectron and the Smart Carb.
The decision was easy honestly. From initial questions to both Nathan and Kim, the quick answers, they made the choice easy. Well here we are. The carb shipped in the quoted time, Kim even sent it expedited so I had it on Friday and not Monday. It arrived packaged well, with instructions, install was a breeze and the bike started 2nd kick. I had the opportunity to ride this weekend and wow. It never idled this well, was as crisp, clean, and you know what…. The temps/humidity didn’t matter, my elevation didn’t matter, I wasn’t jerking around with the Af screw for correct idle. I rode, had a blast, it ran perfect, and I wasn’t stressed about is my jetting right. If you’re on the fence, just do it. It’s so worth the price and the customer service is just as good. (I had a question and the owner answered the phone, while they were closed and helped me) This day and age customer service is long forgotten. These guys have it dialed in and put out a premium product that works! Well done guys!
Charlie –
I have about 4 hrs using the 38mm on my yz250x.I find it works very well,starts easily runs crisp and clean all the way thru.I read people saying the smart carb will make the bike boring.I do not feel this way .The bike has a very connected feel to the rear wheel ,pulls really well even way down low.I just placed another order for my beta hoping for the same result.
Walter Loving –
I purchased a 2020 YZ250X from a local dealership in June of 2020 for the purpose of trail riding with my son who is on a CRF50F. Needless to say I believed the 250x would be a perfect bike for woods riding and slower technical terrain. However, the first day I had it out it fouled a spark plug. The dealer ensured me this was normal for a new bike however, it continued to happen after almost every ride regardless of how much I was on the pipe. The support from the dealership was non-existent as thy suggested riding harder and changing my oil ratios to fix the jetting issues.
I was getting to the point where I wanted to trade the bike in all together, I’m not a mechanic and did not want to mess with jetting or let the dealership charge me more to fix the factory jetting issues the bike left the shop with.
That is when I discovered SmartCarb Fuel Systems! When I called the shop to inquire about their carburetors, the staff was extremely receptive , knowledgeable and helpful. In fact, they offered to look at my bike since I was local. A few weeks later I brought my bike into the shop for a 38mm smart carb which they installed in-house for me.
Having an SC2-Smart Carb on my bike has completely changed my outlook and experience on the bike. For starters I have not fouled a spark plug in months of lugging the bike around at slower speeds with my son which is a gift in it self. Secondly, the bike is nearly impossible to stall during technical riding and the power delivery is much more linear.
I now feel like I have a great bike that I can depend upon and I can share the time I have to ride with my son instead of pushing the bike out of the woods to change the plugs, all thanks to SmartCarb.
Justin A Sadeghian –
Could not be more pleased with the purchase. Have about 60 hours including an off road racing series and multiple track days.
Have a YZ250 but have a 325 kit with a rekluse clutch so was concerned about how the carb would perform. The combo was phenomenal and is testament to how flexible the carb is. Pulls hard off the bottom and is linear all the way through the RPM range
Install was very straightforward, flipped up the rear subframe and had no issues. Would recommend using your phone (or other camera to make sure the there is no obstruction from the air boot, I had to trim mine slightly. Bike literally started in 5 kicks with a new top end. My 2015 YZ250 has no clearance issues with the rear shock either, it initially makes the air box touch until you sit on the bike.
Initial tuning was pretty close from SmartCarb. I really appreciate the fact they listen to each customers specific application and send a tuned carb for your platform with baseline settings written on the manual. I’ve heard complaints about the carb not being capable of change but I’ve had mine from sea level to 5K (MSL) in varying temperature and humidity conditions and I cannot tell the difference between my friends FI bikes and the SmartCarb. Another thing I like compared to FI is you have the capability to adjust to your liking, if the bike is to rich or lean it’s literally a 5 second process to get where you want to be. Additionally I’ve had friends with electronic FI issues, which I never have to worry about.
The off road races started from “dead engine” condition so I’m familiar with starting quickly and the bike fires first kick every time if I do my job. In 60 hours of riding I’ve never had a starting issue.
Fuel economy is dramatically better. Have not done a mileage test but for reference I could run a 2 hour off road race on the stock YZ250 MX tank, which is incredible and couldn’t get anywhere close to that before.
Bottom line, I won’t have a bike with a conventional carb from here on out, really pleased with the product.
Justin