🌿String Trimmer

E07

STIHL · FS 91 R Trimmer

STIHL FS 91 R Trimmer E07 Error Fix: Spark Plug Fouling

This error is caused by a dirty or fouled spark plug, leading to weak or no ignition, resulting in starting issues or engine misfire.

Medium severity2 fixes available

Quick Answer

Error E07 on the STIHL FS 91 R Trimmer means: Spark Plug Fouling. The top-ranked community fix is “Replace Spark Plug” (easy difficulty, ~10 min, DIY cost: $8-$15). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · string trimmer

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

Root Cause Analysis

Ignition FailurePrimary

When to Call a Professional

While many string trimmer repairs can be done safely at home, consider hiring a qualified technician if:

The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $70-$100.

Other STIHL Models with Error E07

BG 86 C-E Blower

leaf_blower · 2 fixes

BGA 57 Battery Blower

leaf_blower · 2 fixes

FS 56 RC-E Trimmer

string_trimmer · 2 fixes

FSA 57 Battery Trimmer

string_trimmer · 2 fixes

MS 180 C-BE Chainsaw

chainsaw · 2 fixes

MS 250 45.4 cc 2-Stroke Gas Chainsaw with 18" Bar and Anti-Vibration System

chainsaw · 2 fixes

MS 271 Farm Boss Chainsaw

chainsaw · 2 fixes

MS 362 C-M Chainsaw

chainsaw · 2 fixes

MSA 220 C-B Battery

chainsaw · 2 fixes

Other STIHL FS 91 R Trimmer Error Codes

DIES AT IDLE

Engine Dies When Idling

Engine Overheating

Fuel Mixture Imbalance

2 fixes

E03

Ignition Coil Failure

Clutch Slippage

Throttle Trigger Malfunction

Air Filter Clogging

Fuel Line Crack or Leak

2 fixes

People Also Ask About STIHL FS 91 R Trimmer Error E07

What does error code E07 mean on a STIHL FS 91 R Trimmer?

Error code E07 on the STIHL FS 91 R Trimmer means: Spark Plug Fouling. This error is caused by a dirty or fouled spark plug, leading to weak or no ignition, resulting in starting issues or engine misfire.

How do I fix error code E07 on my STIHL FS 91 R Trimmer?

The most successful fix is "Replace Spark Plug" (easy difficulty, ~10 minutes). Estimated DIY cost: $8-$15. HomeMD has 2 community-ranked fixes for this error.

Is error code E07 on a STIHL FS 91 R Trimmer serious?

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Can I fix STIHL FS 91 R Trimmer error E07 myself?

Yes — the top-ranked community fix ("Replace Spark Plug") is rated easy difficulty and takes about 10 minutes. Tools needed: Spark plug wrench, Feeler gauge.

How much does it cost to repair STIHL FS 91 R Trimmer error E07?

DIY cost: $8-$15. Professional repair typically costs $70-$100. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the STIHL FS 91 R Trimmer have?

The STIHL FS 91 R Trimmer has 8 other known error codes, including: DIES AT IDLE (Engine Dies When Idling), E01 (Engine Overheating), E02 (Fuel Mixture Imbalance), E03 (Ignition Coil Failure), E04 (Clutch Slippage), and 3 more.

Which other STIHL models have the E07 error?

Error code E07 also appears on 9 other STIHL models: BG 86 C-E Blower, BGA 57 Battery Blower, FS 56 RC-E Trimmer, FSA 57 Battery Trimmer, MS 180 C-BE Chainsaw, MS 250 45.4 cc 2-Stroke Gas Chainsaw with 18" Bar and Anti-Vibration System, and 3 more. The fix may vary by model, so check each model's specific page for tailored repair steps.

What other error codes does the STIHL FS 91 R Trimmer have?

The STIHL FS 91 R Trimmer has 8 other known error codes:

DIES AT IDLE — Engine Dies When Idling (1 fix)
E01 — Engine Overheating (2 fixes)
E02 — Fuel Mixture Imbalance (2 fixes)
E03 — Ignition Coil Failure (2 fixes)
E04 — Clutch Slippage (2 fixes)
E05 — Throttle Trigger Malfunction (2 fixes)
E06 — Air Filter Clogging (2 fixes)
E08 — Fuel Line Crack or Leak (2 fixes)

Which other STIHL models have the E07 error?

Error code E07 also appears on 9 other STIHL models:

BG 86 C-E Blower (leaf blower) · 2 fixes
BGA 57 Battery Blower (leaf blower) · 2 fixes
FS 56 RC-E Trimmer (string trimmer) · 2 fixes
FSA 57 Battery Trimmer (string trimmer) · 2 fixes
MS 180 C-BE Chainsaw (chainsaw) · 2 fixes
MS 250 45.4 cc 2-Stroke Gas Chainsaw with 18" Bar and Anti-Vibration System (chainsaw) · 2 fixes
MS 271 Farm Boss Chainsaw (chainsaw) · 2 fixes
MS 362 C-M Chainsaw (chainsaw) · 2 fixes
MSA 220 C-B Battery (chainsaw) · 2 fixes

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