Stihl MS 500i Review: The Fuel-Injected Revolution in Your Hands
The first time we pulled the starter cord on a Stihl MS 500i, we did not know what to expect. As arborists who have spent decades lugging everything from the nimble Stihl MS 261 to the bone-shaking MS 881, we have grown accustomed to the ritual. Set the choke, pull until it pops, flip the lever, pull again, and hope the carburetor is not feeling temperamental.
With the MS 500i, that ritual is dead. There is no choke. There is no warm-up period. You just prime the bulb, pull, and the engine immediately settles into a digital, predatory idle. This is not just another chainsaw; it is the first mass-produced fuel-injected chainsaw on the planet.
At a Glance: How the MS 500i Stacks Up
| Model | Displacement | Power Output | Weight (Powerhead) | Fuel System |
|---|---|---|---|---|
| Stihl MS 500i | 79.2 cc | 6.7 bhp | 13.7 lbs | Electronically controlled injection |
| Stihl MS 391 | 64.1 cc | 4.4 bhp | 13.7 lbs | Carburetor |
| Husqvarna 460 | 60.3 cc | 3.62 bhp | 12.8 lbs | Carburetor |
| Stihl MS 462 | 72.2 cc | 6.0 bhp | 13.2 lbs | M-Tronic |
Stihl MS 500i Review: The Death of the Carburetor
The heart of the MS 500i is its Injection (i) technology. Inside the MS 500i, a small Electronic Control Unit (ECU) acts as the saw brain, receiving data from an internal pressure sensor, temperature sensor, and position sensor. Because the ECU knows the exact air density and engine state, it adjusts the fuel-to-air ratio in real-time.
We took this saw from sea level to 5,000 feet in a single afternoon. The 500i did not care. It adjusted the timing and fuel delivery before we even made the first notch.
Honest Downside
This is one of the most expensive saws in its class. It drinks fuel—keep your cans full. Electronic issues require specialized diagnostic tools. The plastic latches on the filter cover feel slightly under-engineered for a saw at this price point.
Who It Is Best For
Professional fellers, large-property owners with massive timber, or tool enthusiasts who want the absolute pinnacle of internal combustion technology. If you are just clearing brush on weekends, save your money and buy a Stihl MS 271.
Chainsaw Safety
The MS 500i has zero throttle lag—the acceleration is violent. This saw can get away from inexperienced operators quickly. Always maintain a firm two-handed grip and be prepared for instant chain speed.
Never operate this saw without full PPE. Review our chainsaw safety guide.
Maintenance and Serviceability
The MS 500i uses the HD2 filter system—pleated, large-surface-area, and washable. Spark plug access is straightforward. If the ECU ever fails, you cannot tune it with a screwdriver like a Stihl MS 250; you need a dealer diagnostic. The reliability of EFI outweighs the loss of backyard tunability.
For bar and chain matching, see our stihl-chainsaw-bar-size-guide-match-your-model-to-the-right-bar-chain.
Gas vs Battery
No battery-powered saw comes close to the MS 500i power-to-weight ratio and sustained runtime. In the professional 80cc class, fuel injection has set a new standard that battery technology cannot yet challenge. Read our gas vs electric chainsaw guide.
Final Verdict
The Stihl MS 500i is the best chainsaw we have ever used. Period. Is it for everyone? Absolutely not. If you are just clearing some brush on the weekend, save your money. However, if you are a professional, a large-property owner with massive timber, or simply a tool enthusiast who wants the absolute pinnacle of internal combustion technology, the MS 500i is in a league of its own.
SAWOFF Rating: 4.9 / 5
Get out there and cut. Safely.
Frequently Asked Questions
Does the Stihl MS 500i have a battery?
No. The energy required to run the electronics is generated by the flywheel as you pull the starter cord. This is why you usually need to give the primer bulb 5-8 pushes to ensure fuel is in the lines before that first pull.
Can I use regular gas in my MS 500i?
You can, but we strongly recommend 91+ octane ethanol-free fuel. Ethanol attracts moisture and can gum up the expensive injector nozzle. If you must use ethanol fuel, use a high-quality stabilizer and never let it sit in the saw for more than 30 days.
How does the 500i compare to the MS 462?
The MS 462 is a fantastic saw and slightly lighter, but it is carbureted (M-Tronic). The 500i has significantly more grunt in big wood. If you are consistently cutting wood over 20 inches, the 500i is the clear winner.
Why is my MS 500i hard to start when hot?
The 500i is famous for hot-start reliability because EFI prevents vapor lock. If you are having trouble, check your air filter. A clogged HD2 filter can mess with the pressure sensor readings.
What bar length is best for the MS 500i?
The 500i can pull a 36-inch bar in a pinch, but it really shines with a 20-inch to 28-inch bar. We personally run a 25-inch Light bar for the best balance.
Do I need to tune the EFI?
No. There are no high/low adjustment screws on the MS 500i. The ECU tunes itself hundreds of times per second. If the saw runs poorly, it is likely a mechanical issue (dirty filter, bad plug, or air leak).
Is the fuel injection reliable in the long run?
Field reports have been overwhelmingly positive. The technology was tested in Stihl TS 500i concrete saws for years before hitting chainsaws. Concrete saws live in the most brutal environments imaginable and the injection systems held up.
What is the weight of the MS 500i?
The MS 500i powerhead weighs 13.7 lbs (6.2 kg), remarkably light for an 80cc-class saw producing 6.7 bhp.
