Shop replacement repair parts for Stihl String Trimmer model FS 110

Recoil starter assembly
Service your Stihl FS 110 string trimmer with genuine OEM replacement parts from Repair Clinic. The Stihl FS 110 is a 35.2cc four-stroke equivalent stratified-charge two-stroke engine trimmer in Stihl’s professional FS series, positioned above the 27.2cc FS 80 and FS 85 in the commercial trimmer line. The FS 110 R is the bike-handle variant of the same platform; stihl fs110r parts including the carburetor, ignition coil, air filter, and fuel lines are shared with the FS 110 loop-handle variant. The FS 100 designation in some search queries refers to the same FS 110 platform in certain market designations; fs 110 stihl parts apply equally. Parts most frequently required include the carburetor, spark plug, air filter, fuel lines, primer bulb, and trimmer head. Use the stihl fs 110 parts diagram and FS 110 parts list to identify your component, then browse the complete Stihl trimmer parts catalog.
The Stihl FS 110 uses a 35.2cc stratified-charge two-stroke engine that Stihl designates as a 4-MIX engine in some documentation; this engine runs on a 50:1 gasoline-to-two-stroke-oil mixture and produces higher torque at lower RPM than the 27.2cc engines in the FS 80 and FS 85. The increased displacement and torque make the FS 110 better suited for sustained cutting in heavy brush and tall grass than the 27.2cc models, but also means the carburetor and ignition system are calibrated for a different power output range. The stihl fs110r parts diagram and stihl fs 110 r parts diagram on the listing page show the same engine and fuel system section for the R bike-handle variant as for the standard loop-handle FS 110. The FS 110 parts diagram includes the stihl weed eater fs 110 r parts diagram section for the handle assembly; the engine components are identical between the two handle configurations. The stihl FS 100 parts diagram designation in some searches refers to the same FS 110 platform documentation. The Stihl FS 100 manual and FS 110 manual document the correct spark plug electrode gap, fuel mixture ratio, and carburetor adjustment procedure. For repair guidance, visit the Stihl trimmer repair help section.
The Stihl FS 110 carburetor is a diaphragm-type unit calibrated for the 35.2cc engine’s higher fuel demand compared to 27.2cc models. Ethanol-blend fuel varnish deposits on the diaphragm, needle seat, and main jet passages produce hard starting, lean-running at full throttle, and stalling under heavy brush load. In commercial applications where the FS 110 accumulates high seasonal hours, varnish deposits may form even within a single season if fuel sits in the system between jobs. Replace the carburetor when cleaning with solvent does not fully restore starting and full-throttle performance. Browse Stihl trimmer carburetor parts.
The Stihl FS 110 spark plug should be replaced at the start of each season and inspected at mid-season in commercial applications where the trimmer accumulates 100 or more hours per season. The 35.2cc engine produces more combustion heat per cycle than 27.2cc models; a plug that is approaching end-of-life causes hesitation and power loss under the sustained heavy loads commercial FS 110 operation demands. Confirm the electrode gap from the Stihl FS 100 manual or FS 110 manual before installation; the 35.2cc engine is sensitive to gap deviation at high RPM.
The fuel lines on the FS 110 string trimmer are short rubber segments that stiffen and develop micro-cracks through ethanol-blend fuel exposure. Air leaks through cracked fuel lines produce lean-running at full throttle under the high fuel demand of the 35.2cc engine, creating a symptom pattern that can be misidentified as a carburetor main circuit fault. Replace the complete fuel line kit and primer bulb as a set alongside any carburetor service to prevent the new carburetor from exhibiting the same symptoms from cracked lines within a short operating period.
The trimmer head on the Stihl FS 110 and fs110r wears through extended commercial use. The bump-feed advance mechanism’s guide tabs and bump pad deteriorate, causing advance failure while line remains on the spool. When ordering a replacement trimmer head for the fs110r, confirm the shaft configuration matches; the bike-handle fs110r uses the same head thread specification as the loop-handle FS 110, but confirm against the stihl fs110r parts diagram before ordering.
The Stihl FS 110 uses a 35.2cc engine while the FS 80 and FS 85 use 27.2cc engines. The FS 110 produces higher torque at lower RPM, making it better suited for heavy brush and tall grass in sustained commercial use. The carburetor, spark plug, and fuel line specifications differ between the 35.2cc and 27.2cc platforms; parts from the FS 80 or FS 85 are not interchangeable with FS 110 components.
Yes for engine components. The stihl fs110r and FS 110 share the same 35.2cc engine, carburetor, air filter, fuel lines, primer bulb, ignition coil, and spark plug. The fs110r uses a bike handle instead of a loop handle; handle assembly components and some shaft components differ between the two configurations. Confirm trimmer head and handle parts against the stihl fs110r parts diagram before ordering these components.
The Stihl FS 110 carburetor is identified by the part number in the stihl fs 110 parts diagram carburetor section on the listing page. Navigate to the carburetor subsection and match the callout number to the parts list to confirm the correct replacement carburetor model. Stihl uses Zama and Walbro carburetors across FS 110 production; confirm the specific carburetor brand and model from the diagram for your unit before ordering a rebuild kit or replacement.
An FS 110 that loses power under heavy brush load after carburetor service most commonly has a fuel line air leak that was not addressed alongside the carburetor replacement. At the high fuel demand the 35.2cc engine creates under full-load cutting, a small fuel line crack produces a significant lean condition. Replace the complete fuel line kit and primer bulb if they were not replaced at the same time as the carburetor; also confirm the air filter is clean and the spark plug gap is correct for the 35.2cc engine specification.

Family-owned and operated since 1912, Burke America Parts Group is the longest-running genuine appliance, HVAC, and outdoor power equipment parts solution in North America. At Repair Clinic, we're proud to be an international brand trusted by the pros as well as the DIY community.
About Repair Clinic