This usually means the engine isn't getting enough fuel when you open the throttle. Let's walk through it step-by-step.
First, you'll want to check the air filter. A dirty filter chokes the engine. Remove it, tap it clean, or wash it if it's the felt type. Let it dry completely before putting it back.
If the filter is clean, the issue is likely in the fuel system. Here's what to do:
- Drain the fuel tank completely. Old fuel goes bad and gums things up.
- Refill with fresh, properly mixed fuel. Use the exact oil-to-gas ratio specified for your saw.
- Check the fuel filter inside the tank. If it's dark or clogged, it needs to be replaced.
If that didn't work, the carburetor's high-speed circuit might be clogged or out of adjustment. This requires a special tool and some know-how. If you're not comfortable, this is the point to take it to a STIHL dealer for service.
A quick tip: Always use fresh fuel mix, and run the saw dry if you're storing it for more than a month to prevent this.