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Description
4128 121 8901 STIHL Pin – Genuine OEM Part
The STIHL Pin (4128 121 8901) is a genuine OEM replacement component designed for use in the carburetor assemblies of many STIHL professional brushcutters, backpack blowers, hedge trimmers, sprayers, and KombiSystem units. This pin is a critical small hardware part that helps secure internal carburetor components, ensuring correct fuel metering and dependable engine operation.
Manufactured to STIHL’s exact specifications, this OEM pin ensures proper fitment, long-lasting durability, and reliable performance when replacing worn or missing carburetor parts.
Product Details
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OEM Part Number: 4128 121 8901
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Brand: STIHL (OEM)
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Part Type: Pin
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Application: Carburetor Assembly (C1Q / C1M Series)
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Condition: New Genuine OEM Part
Function
This pin is designed to:
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Secure internal carburetor components in position
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Support proper fuel metering and engine performance
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Replace worn, bent, or missing carburetor pins
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Restore correct carburetor function
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Maintain reliable starting and smooth running
⚠️ A damaged or missing pin may lead to fuel delivery issues or poor engine operation.
Verify Fitment in 30 Seconds
Before ordering, confirm the following:
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OEM part number 4128 121 8901
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Part location: carburetor assembly
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Compatible STIHL model listed below
⚠️ Always verify fitment by OEM part number for best accuracy.
Compatibility
Fits a wide range of STIHL equipment, including:
Brushcutters / Trimmers
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FS 90, FS 90 R
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FS 100 RX
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FS 110, FS 110 R, FS 110 RX
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FS 120, FS 120 R
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FS 130, FS 130 R
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FS 200 R
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FS 250, FS 250 R
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FS 310, FS 350
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FS 450-K
KombiSystem Units
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KM 90 R
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KM 110 R
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KM 130 R
Backpack Blowers
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BR 200
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BR 350
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BR 430
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BR 450, BR 450 C-EF
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BR 500
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BR 550
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BR 600
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BR 700, BR 700 X
Sprayers / Mistblowers
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SR 200
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SR 430
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SR 450
Hedge Trimmers
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HS 45
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HS 81 R, HS 81 T, HS 81 TC-E
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HS 82 R, HS 82 T
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HS 86 R, HS 86 T
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HS 87 R, HS 87 T
Pole Pruners / Long Reach Units
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HL 90 K
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HL 100, HL 100 K
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HT 100, HT 101
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HT 130
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HT 250
Specialty Units
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FC 90, FC 95, FC 100
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FC 110
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BT 120 C, BT 121
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SP 200
⚠️ This list includes common applications — always confirm using your parts diagram or owner’s manual.
Installation / Usage
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Turn off engine and allow it to cool completely
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Remove air filter housing and carburetor access components
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Disassemble carburetor carefully in a clean workspace
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Replace the worn or missing pin with the new STIHL OEM part
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Reassemble carburetor and test engine operation
⚠️ Carburetor service should be performed by a qualified technician if unsure.
Maintenance Tips
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Use fresh fuel and proper fuel mix ratios
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Keep air filters clean to prevent carb contamination
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Inspect carburetor hardware regularly for wear
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Replace damaged pins immediately to avoid running issues
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Use only genuine STIHL replacement parts for best fit and reliability
