SIMPERAC FS91R Carburetor for Stihl Weedeater — Fits FS91R/FS111R/FS89 KM91R KM111R

Overview

The SIMPERAC FS91R carburetor is designed as a robust replacement for Stihl engines and is compatible with a range of models in the FS and KM series. Built to support precise air–fuel delivery, this unit aims to restore steady startup and responsive throttle during yard work such as trimming, edging, and light brushing.

Compatibility and model fit

This carburetor replaces Stihl 4180-120-0615 and is suitable for the FS91R family as well as related KM-series Kombi engines. You may also find compatibility with FS89/FS91/FS111R variants and other listed Stihl models like HT102/HT103 pole pruners and FC-series lawn edgers. Always compare your engine model with the images provided to confirm the exact match.

• FS91R, FS111R, FS89 variants
• KM91R and KM111R Kombi engines
• HT102/HT103 pole pruners and FC91/FC96/FC111 edgers

What’s included in the kit

• 1 carburetor
• 1 air filter
• 1 fuel line
• 1 spark plug
• 2 fuel filters
• 2 gaskets
• 2 primer bulbs
• 1 carburetor adjusting tool

Why this matters for your outdoor work

While results can vary by machine and usage, this kit is designed to help restore a consistent air–fuel mix, reduce leaks that affect performance, and support cleaner combustion. You may notice quicker starts, steadier idles, and smoother throttle response when performing tasks like edging and light clearing.

Real-world use cases

Imagine a weekend project where you need reliable power at varying speeds. With a refreshed carburetor, you may experience a steadier pull on the trigger, improved idling, and consistent performance through a row of hedges or a brushy edge along a fence line.

Installation tips and care

• Check your engine model and compare with the listing images before swapping parts.
• Replace the air filter and inspect the fuel line for wear during installation.
• Use the included adjusting tool to set idle and mixture as directed by your manual or trusted guidance.
• Keep the gaskets and primers in good condition to maintain a tight seal and prevent leaks.

Quality and support

Designed for compatibility with standard Stihl fittings, the SIMPERAC FS91R carburetor aims to support reliable field performance. For best results, ensure compatibility with your exact model and follow safe maintenance practices. This kit provides all essential components for a complete rebuild in one package.