It’s safe to say that snowmobiles today come with fuel injected engines, including 2- and 4-stroke models. Before 1991, vintage snowmobiles were exclusively manufactured with carburetors, but in the ‘90s, fuel injected models became more and more prevalent.
If you would like to find out more about snowmobile fuel injection system (known as EFI), this post is for you.
We at PowerSportsGuide have compiled all you need to know about this advanced technology under one roof!
Are Snowmobiles Fuel Injected?
A few decades ago, vintage snowmobiles were powered exclusively by 2-stroke engines with most of them utilizing carburetors provided by an external manufacturer.
The early models typically had Tillotson carbs, but later the industry started using the more advanced Mikuni carbs.
But everything changed in 1991 when Polaris revealed the world’s first stock fuel injected snowmobile, the 1991 Indy 650 RXL EFI.
Forced by the tightening of EPA emission regulations in the early ‘90s, competitor manufacturers also started moving towards this technology.
By the mid-2000s, carbureted engines were no longer being used in snowmobiles to make room for the more advanced fuel-injected power plants.
This innovative technology allowed 2-stroke snowmobile engines to remain in production to the delight of many mountain riders!
What does EFI mean on a Snowmobile?
Simply put, on a snowmobile EFI stands for Electronic Fuel Injection. EFI is typically not listed with the names of today’s snowmobiles as all models come with this feature as standard.
The first fuel-injected snowmobiles utilized a semi-direct fuel injection systems (SDI) that typically used two injectors per cylinder, one “low-speed” and one “high-speed” unit. In contrast, more advanced snowmobiles come powered with electronically-controlled EFI engines that feature one injector per cylinder.
Are you wondering how this system works? Keep reading!
How does Fuel Injection (EFI) Work on a Snowmobile?
As its name suggests, a snowmobile’s fuel injection system (EFI) is designed to inject fuel straight into the engine. The system uses a set of fuel injectors that atomize the gas at high pressure and force it into the cylinders or the inlet manifolds. The amount of fuel is electronically adjusted based on environmental conditions like the elevation or temperature.
This means a snowmobile’s EFI does the same job as the carburetors, but it does it in a more advanced way.
Besides the injectors, the EFI system utilizes many other key features like sensors, pressure regulators, a fuel pump, and a computer. The latter is the “brain” of the system and often referred to as the Electronic Control Unit (ECU).
The longer the injectors are open, the more fuel they pressure into the cylinders. If the sensors detect that the engine is getting too much fuel, the computer adjusts the injectors to be open for a shorter time. It is as simple as it sounds!
In contrast, a carbureted snowmobile engine couldn’t automatically adjust itself. Because of this, it was less reliable and required far more attention.
Although nowadays you can mainly find fuel-injected snowmobiles off the shelf, vintage carbureted models are still popular on the used market. Therefore, it makes sense to compare these different systems head-to-head!
Snowmobile EFI vs. Carburetors
In a nutshell, the major pros and cons of EFI snowmobile engines are as follows:
Pros of snowmobile EFI
- Better fuel and oil economy
- Cleaner operation
- No jetting required for changes in elevation and temperature
- Easier starts (especially if the engine is cold)
- Requires less maintenance and attention (no carbs to clean, adjust, or rebuild)
- Higher reliability and durability
- Overall better performance (smoother acceleration, more power)
Cons of snowmobile EFI
- More complex system with many electronics
- More parts to fail (most of them are very costly)
- Harder to diagnose and fix problems, especially at home
- It makes the sled harder to tune
- Extra weight because of the battery (if featured)
- More expensive to manufacture
Let’s get down to the nitty-gritty and talk about each of these factors in detail!
Pros of Snowmobile EFI
There’s no question that the main advantage of having an EFI system on a snowmobile is that it makes the starts much easier, especially if the engine is cold.
You can just pull-start the sled and ride regardless of the elevation or the outside temperature. As a rule of thumb, fuel-injected snowmobiles start with 1-3 pulls while their carbureted counterparts are usually much harder to start.
The key advantage of EFI snowmobiles is that they don’t require rejetting for changes in elevation and temperature.
Changing the jets to compensate for the changes is always a headache; this is why EFI snowmobiles instantly became popular among mountain riders.
Besides, these engines require much less attention and maintenance as well.
What’s more, EFI snowmobiles are not only more reliable, but it is much harder to clean out their engines. They also have a better overall performance as they crank out more HP and have a much smoother acceleration.
Despite the additional power, EFI snowmobile engines are more fuel-efficient and environmentally friendly than their carbureted brothers.
Cons of Snowmobile EFI Systems
Riders agree that the main disadvantage of the snowmobile fuel injection system is its complex design.
Compared to simple mechanical carbs, an EFI system features a lot more parts with many of them being electronics related. They cause a huge mess under the hood, which means more units that may malfunction.
And as you might assume, it is much harder to work on an EFI system than on regular carbs. EFIs typically require a diagnostic cable and software to diagnose errors or adjust the fuel supply.
On a carbureted sled, you can typically isolate and fix the problem much easier and set the jetting based on your needs.
If the EFI’s computer (ECU) fails, the replacement costs you hundreds of dollars. In contrast, carbs have a much simpler design, and their replacement parts cost almost nothing. It is also good to know that the EFI system makes the sled harder to tune.
It’s also good to know that most fuel injected snowmobiles utilize a battery, which means extra weight and a source of error.
Early EFI sleds were especially sensitive to battery voltage, so they required a good and properly charged battery. This is why the innovative batteryless EFI snowmobiles became far more popular than regular models.
Finally, EFI systems are more expensive to manufacture, which is reflected in the prices of the sleds.
Takeaways – FAQs about Fuel Injected Snowmobiles
Are new snowmobiles fuel injected?
Yes, it’s safe to say that all new snowmobiles are fuel injected.
Can a 2-stroke snowmobile engine be fuel injected?
Yes, many snowmobiles are powered by 2-stroke EFI engines.
When did snowmobiles get fuel injection?
The snowmobile industry switched to fuel injection from carburetors in the early 1990s.
When was the first fuel injected snowmobile?
The first fuel injected snowmobile was the 1991 Polaris Indy 650 RXL EFI, powered by a 648cc, 3-cylinder, Fuji engine.
When did Ski-Doo go fuel injected?
The first fuel-injected Ski-Doo, the limited-edition Formula Plus EFI, was revealed in 1993.
When did Arctic Cat snowmobiles go fuel injected?
Arctic Cat introduced their first fuel injected snowmobiles in the 1991 model year. These sleds were the 1991 Arctic Cat Wildcat 700 EFI, and the Wildcat 700 EFI MC (Mountain Cat).
When did Polaris snowmobiles go to EFI?
Polaris introduced its first EFI snowmobile, the Indy 650 RXL EFI in 1991.
When did Yamaha snowmobiles go fuel injected?
Surprisingly Yamaha was the last of the four major manufacturers that moved towards fuel-injected technology. The first Yamaha EFI snowmobiles were the 2006 Yamaha APEX GT, RTX, and Mountain models, while the Apex ER still came with carburetors.
Do all EFI snowmobiles feature a battery?
No surprisingly, all EFI snowmobiles originally came with a battery. The first “batteryless EFI snowmobile” was the ZR 580 EFI introduced by Arctic Cat in 1997.