EFI 2 Strokes - Can they save the sport ?

Fuel-injected 2 Stroke motocross bikes will come when the manufacturers believe that they are ready for prime-time or that the market is willing to bear the brunt of the change or when government cracks down on them. Fuel injection will not change how you ride your bike.

It was an open secret but finally confirmed what we all were expecting. 2 Stroke electronic injection reaches KTM. Will do so in the 2018 range of enduro bikes?

The entry into force of Euro 4 in 2017 and high pollutant gas restrictions has forced manufacturers to take drastic measures in their production if they wanted to continue to keep their catalog of 2 Stroke Enduro bikes.

Mattighofen been working for several years on a new engine with 250 and 300 2 strokes with electronic injection. It is no secret that KTM has been testing fuel-injection on two-strokes for some time. They have been as quiet as possible about it. Until Now.

Now at the Roof Of Africa the secret isn’t being hidden at all. FI equipped KTM 300s ran in a race that had a big variation in both elevation and temperature to shake out the bugs. A great real-world look at how fuel injection can benefit a two-stroke.

The reason for resisting FI has been cost and complexity but times are changing. With new emissions standards coming quickly in Europe and the popularity of the two-stroke world-wide, something must give.

The parts on the bikes at the Roof of Africa are very production looking and could be sourced from current four-strokes for the most part. The complexity is in the electronics controlling the system. Current 2 strokes already have the power to run the system and squirting fuel into an engine through an injector is nothing new. Having a little pre-mix blended in does not cause any issues. Oil Injection will make future systems even better.

The cost of carburetors is increasing to a point where the FI parts may be even be less expensive in total. From a production standpoint, it is the development time to get the mapping right that saddles the cost. 2 strokes are said to present some unique issues due to wildly varying exhaust temperatures and differing compression ratios based on RPM and exhaust valve movement– yet somehow the antiquated carb deals with these issues just fine. Or did they? Time will tell.

The advantages of EFI are many. Like increased fuel efficiency, longer power spreads, less loading up and even better throttle response. Sherco has a running FI 2 stroke and Ossa has a production 2 stroke trials bike that is FI.

When will we see this? We cannot be sure but an educated guess is 2019 for full production from KTM and Husqvarna. Do not be surprised if you see a “special factory edition” type from KTM even sooner.

One of the future big decisions will be whether to invest in a two-stroke or four-stroke engine. With the proliferation of misinformation regarding this subject, it’s easy to confuse fact and fiction. Not to worry. We’ll walk you through the fundamentals and add some clarity to the subject.

MX Sports should change the rules to equalize the displacement in both the 250 and 450 outdoor MX classes. The powers-that-be could easily write a rule that says, “The maximum displacement in the 250 class is 250cc regardless of the engine type and in the 450 class it is 450cc regardless of engine type.”

This simple rewording of the current rules would spice up modern racing, by bringing competition into racing not just between riders and brands, but between engine types. It would also provide cheaper racing for riders on a budget. While there are no 450cc two-strokes currently in production, you could start with 300cc bikes for now (and just as they did with four-strokes initially, give Open class two-strokes an exemption to allow them to build big bores to compete on). This could encourage manufacturers to pursue more market share with 2 Strokes—since they aren’t setting the world on fire with four-stroke anymore.

And add a 125 Pro 2 Stroke Class at Select Nationals as an East/ West series with a final shootout in the existing National MX Series. Kind of Like the Youthstream has done with 2 Strokes in Europe?


EFI has been developed for 2-strokes and is having it's heyday in outboard marine engines. What does this mean to MX bikes?

An EFI 2-stroke is as clean, if not cleaner than a 4-stroke from an emissions perspective. In developing countries, the 2-stroke (say a scooter of 100-125cc) is something that can economical to manufacture, and which people can afford to buy. With millions of these being produced in places like China and Pakistan, with millions of people driving them in those countries, you want them as clean as possible, and for the 2-stroke, EFI is the solution.....

EFI would make more sense for the trail rider. Trail riders in Colorado for example are regularly in different altitudes and changing weather conditions more often than anyone riding at a track. Having a 2 stroke with perfect jetting at altitude is not something that can be accomplished with carburation.

Do not doubt the industry is enjoying the extra cost of the fourstroke era. Why are the silencers $300 anyway? They don't look any different than the 2 stroke silencers. But remember people saying the same thing when radiators were added, and disc brakes? and aluminum frames ? Yes modern bikes cost double the price they were twenty years ago, even taking inflation into consideration, but they are more reliable, have more power, and have better suspension than was available just a few short years ago.

Is it worth the extra cost? We must think it is because we are still buying bikes and what we buy drives the market. If nobody bought 4 Strokes with EFI, the factories would stop making them.

Honestly, you have to believe that if the 2-stroke dies, the sport may very likely go with it. We need cheap, easy to maintain bikes, so that future generations can afford to get into this sport to begin with.

And an EFI two-stroke would give anyone a "Boner"

How To Decide Between a 2 Stroke or 4 Stroke Outboard Boat Engine - Excerpt from gameandfishmag.com

TWO-STROKES

In a two-stroke engine, the fuel-air mixture enters the combustion chamber via a port in the side of the cylinder. The exhaust exits through another port in the cylinder.

Initially, two-stroke engines used carburetors to control the fuel-air mixture. But carbureted 2 Strokes aren’t particularly efficient. They also use a lot of fuel, and tend to be cantankerous creatures.

Today’s top-of-the-line Outboard two-stroke engines use a computerized Direct Fuel Injection (DFI) system to precisely regulate the fuel-air mix to suit the operating conditions. That results in amazing performance gains as well as great fuel economy and low emissions.

Typically, a two-stroke outboard is lighter than a similar-sized four-stroke engine because the two-stroke’s method of operation doesn’t require a valve train — camshafts, valves, belts or chains. Since the two-stroke isn’t encumbered with a valve train, the engine has fewer moving parts. Thus, it has less rotating mass and is lighter. A two-stroke outboard can often accelerate faster than the same horsepower four-stroke.

The engine’s internal components receive lubrication from oil mixed into the fuel.

Contrary to popular belief, two-strokes aren’t a dying breed. The fact is, carbureted two-strokes are going away due to their inability to comply with increasingly stringent emissions legislation. However, the DFI two-stroke outboards are thriving and remain popular.

FOUR-STROKES

Because of the valve train, a four-stroke outboard is usually heavier than a two-stroke outboard of the same horsepower. But, four-stroke manufacturers continue to pursue new ways to lighten the engines and extract more horsepower.

A four-stroke outboard’s lubrication system is like a car’s, complete with oil pan and filter — and the engine needs periodic oil changes to keep things running smooth.

The Majority of four-stroke outboards feature sophisticated computer engine management systems and fuel injection for good performance across the power band, low emissions, and fuel economy.

CHOOSE YOUR OUTBOARD

From an angler’s perspective, a boat is nothing but a means to get to where the fish are — a fishing platform — and the outboard is the driving force behind the boat. Tools of the trade, so to speak.

Taking that point of view, how do you pick the right outboard for your boat? Two-stroke or four-stroke — the broad answer is, it depends.

It depends on how you fish, where you fish, what kind of boat, and how much gear you carry with you.

If you’re a dedicated tournament angler, then you need an outboard that will pop the boat up on plane quickly and maximum top-end speed to get to the honey-holes before your competition does. In this case, a two-stroke will fill the bill nicely.

The kind of boat also dictates the best engine. For example, every boat has a placard stating the boat’s weight capacity; a smaller boat may not be able to tolerate the additional weight of a four-sttroke outboard. On the other hand, if your rig is one of the newer mega-boats — 21 feet plus, or if you fish alone and don’t take a bunch of extra stuff with you — then you can start looking at four-strokes.

A big boat or heavily loaded boat can benefit from the torque of a four-stroke outboard.

On the economic and practicality front, it’s important to consider who is going to service the engine and be there for you to take care of any potential warranty issues.

BOTTOM LINE

Fuel economy, emissions and speed are comparable between two-strokes and four-strokes. Two-strokes tend to weigh less but can accelerate faster. Four-strokes tend to have more torque than two-stroke outboards.

Both technologies are solid and highly evolved. Each has advantages and disadvantages.

Now you have a better idea which is the best for the transom of your fishing boat.

How about your Dirt Bike ?