Can a 2-stroke engine be fuel injected?
KTM doesn’t want to be caught with its pants down, so in 2020, every KTM and Husqvarna offroad two-stroke model will be fuel-injected. At this moment in time, that does not included its motocross models, but as MXA has proven over the last year, fuel-injected motocross bikes are a real possibility.
How much HP does direct injection add?
about 10 extra horsepower
When looking at pure horsepower, the fuel injection system only delivers about 10 extra horsepower at peak. It is the ability to constantly be tuning the fuel and air intake for each cylinder that benefits the performance.

Can you run a straight pipe on a 2-stroke?
The right length pipe can actually help a two stroke. Yes you can run a straight pipe. In reality the majority of mufflers used on aero gas two strokes are not all that much different in performance than a straight pipe.
What year did KTM go to TPI?
For 2019 KTM began offering U.S. customers the 300 XC-W model with (TPI) and oil injection. The fuel injected 300’s were previously available only in the international market.

What is the fastest 2-stroke?
These Are The Most Powerful 2-Stroke Sportbikes Ever Made
- 4 Honda NS500 – 123 HP.
- 5 Kawasaki KR500 – 120 HP.
- 6 Yamaha TZ750 – 120 HP.
- 7 1998 Bimota V Due Evolution – 110 HP.
- 8 Suzuki RG500 – 95 HP.
- 9 Yamaha RD500LC – 90 HP.
- 10 Vins Duecinquanta – 80 HP. via topspeed.
- 11 Kawasaki H2 Mach IV 750 – 74 HP. via cycleworld.
What are the disadvantages of direct injection?
Just as plaque can build up in your arteries, reduce blood flow to your heart and lead to a heart attack, carbon buildup on your car’s intake valves reduces fuel flow to the engine and can lead to failure. The biggest drawback of direct fuel injection is DI can lead to clogged fuel systems and engine carbon fill up.
Does 2 stroke need back pressure?
For a 2-stroke engine, the least amount of back pressure inside the exhaust the better. If you look at performance chainsaws (yah, it’s a real thing), you’ll see an exhaust system which has a broad section in the middle of the pipe, then goes back to a smaller size.
What happens if you run a 2 stroke without an exhaust?
Can You Run A 2 Stroke Without Exhaust? It might be possible to start it, but it will run very inefficiently since 2-stroke engines rely on the backpressure in the exhaust to run properly, and much of the fuel will be ejected.
Are KTM 2-stroke fuel injected?
KTM has announced their full range of 2023 SX and SX-F (& XC) motocross models hosting a bag full of updates to engines and chassis’ but new fuel injected two-stroke engines and a full-power, 300 SX steal the show.
Does direct injection make noise?
A direct injection fuel system produces a rapid clicking and ticking sound that can be heard from the engine compartment. The sound is more evident when outside the vehicle or when the hood is open. The sound is more noticeable during idle and is more frequent during a cold start, but lessens once the engine is warm.
Why do 2 strokes have a big exhaust?
On a two-stroke engine, an expansion chamber or tuned pipe is a tuned exhaust system used to enhance its power output by improving its volumetric efficiency.
Do 2 strokes need back pressure?
Why do 2 strokes have big exhaust?
That bulge is called an expansion chamber, and it is used to increase the horsepower of the engine (see this page for a photo). This technique only works on two-stroke engines, which is why you see it on a lot of dirt bikes but not on street bikes. Most street bikes use four-stroke engines.
What is the difference between TPI and TBI?
TBI is basically a high tech carb. The injectors are mounted in the throttle body. TPI is usually multiport fuel injection. There is one injector per cylinder, therefore more effective.
How does a two-stroke dirt bike exhaust system work?
Choosing the correct exhaust system is critical for any two-stroke dirt bike. One of the visible features of a two-stroke exhaust is the oversize bulge in the downpipe. This bulge is actually an expansion chamber which helps the engine develop more power. The expansion chamber works in the same way as a turbocharger, minus the complicated parts.
How much fuel does a two-stroke motor escape from the exhaust?
This was especially evident at low speeds when up to 40 percent of the fuel entering a traditional two-stroke motor escaped unburned. At its most efficient speed, generally 4000 to 4500 rpm, a traditional two-stroke may still expel eight percent of its fuel with the exhaust.
How does a two-stroke engine work?
In a two-stroke engine the rising and falling piston covers and uncovers ports in each cylinder through which a fuel/air mixture flows into, and exhaust flows out of, the combustion chamber.
What is a DFI two-stroke motor?
Modern DFI two-strokes utilize injectors like this one from the Evinrude ETEC line, to gain a huge efficiency boost. Two-stroke outboard motors with DFI (direct fuel injection) were developed in response to an EPA mandate requiring a 75 percent reduction in exhaust emissions between 1998 and 2006.