STIHL Cylinder with Piston 54mm for 066 and MS660 - Genuine OEM - 1122 020 1209

The STIHL Cylinder with Piston 54mm (part number 1122 020 1209) is a genuine OEM top-end assembly for the STIHL 066 and MS660 chainsaws, supplied as a complete kit including the 54mm chrome-lined cylinder, matched piston, two piston rings, gudgeon pin, circlips and decompression valve. Restores compression, power delivery and starting reliability on a worn or damaged top end, returning the engine to original specification. Available from Gustharts, an authorised STIHL dealer with UK stock ready to ship.

⚠ This part fits 066 and MS660 chainsaws manufactured before July 2003 only. Machines produced from July 2003 onwards require part number 1122 020 1211, which is a separate component. Always confirm your machine's serial number and production date before ordering. Contact Gustharts with your serial number if you need confirmation.

Note: 1122 020 1209 and 1122 020 1211 are not interchangeable. They are different parts for different production runs of the same model — not alternate formats of the same number.

Key Features

• Genuine STIHL OEM top-end assembly — manufactured to original specification for correct bore geometry, compression ratio and thermal management
• Part number 1122 020 1209 — also referenced as 1122-020-1209 and 11220201209; fits 066 and MS660 before July 2003 only
• 54mm chrome-plated bore cylinder — original-specification chrome lining for durability, low friction and heat dissipation in sustained heavy-duty cutting
• Complete kit — cylinder, piston, two piston rings, gudgeon pin, circlips and decompression valve supplied as a matched assembly
• Restores compression and power — returns worn, scored or seized engines to original displacement and compression specification
• Matched piston and bore — factory-clearanced piston-to-bore fit prevents premature ring and bore wear during run-in
• Decompression valve included — the MS660's decompression system reduces starting effort; supplied as part of this assembly
• Precision machined mating surfaces — correct head gasket seating and port alignment for proper gas flow and combustion

Technical Specification

Why Choose a Genuine STIHL Cylinder Assembly?

The MS660 is STIHL's largest-displacement production chainsaw at 91.6cc — a 5.2kW professional tool used in demanding timber processing, large-section felling and heavy arborist work where sustained full-load running is the norm rather than the exception. At this power level, the cylinder and piston assembly operates under significant thermal and mechanical stress. Bore geometry, chrome layer thickness, piston ring end-gap and piston-to-bore clearance are all tightly toleranced at the factory specifically for these conditions.

Aftermarket top-end kits are widely available for the MS660 at significantly lower cost. Many use Nikasil-lined bores rather than the chrome plating of the original, which has different run-in requirements and can behave differently under the thermal cycling typical of professional forestry use. Chrome-lined cylinders are generally more tolerant of contaminated fuel and abrasive airborne particles — relevant considerations for an MS660 running in dusty site conditions. The OEM piston-to-bore clearance is factory-set and tested; aftermarket kits vary in whether this clearance is correctly matched to the chrome bore specification. For a component where a seizure means engine destruction on a saw of this value, the cost difference between genuine and aftermarket rarely justifies the risk.

Also Known As

The STIHL cylinder with piston assembly is also referred to as a top-end rebuild kit, pot and piston kit, barrel and piston assembly, jug and piston set, cylinder head and piston assembly, and engine top-end kit. For the MS660 and 066 specifically, it is commonly searched as a MS660 cylinder kit, 066 top-end kit or MS660 bore kit. For correct ordering, always use STIHL part number 1122 020 1209 for pre-July 2003 machines, or 1122 020 1211 for July 2003 onwards, and confirm your production date before purchasing.

Often Replaced Alongside

A top-end rebuild on the MS660 is a natural point to inspect and replace related components that share the same service interval or are disturbed during cylinder removal:

• Head gasket and cylinder gasket set for MS650/MS660 (1122 007 1053) — always fit new gaskets when replacing the cylinder; do not reuse old gaskets
• Decompression valve for MS660 (1128 020 9400) — inspect when the cylinder is removed; replace if the valve seat shows wear
• Spark plug (NGK BPMR7A) — replace at every top-end rebuild as standard service practice
• STIHL chain oil and 2-stroke oil — correct run-in lubrication is essential when commissioning a new cylinder assembly

Explore More

• STIHL Spare Parts
• STIHL Parts Finder
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FAQs

Which machines does part 1122 020 1209 fit?

This part fits STIHL 066 and MS660 chainsaws manufactured before July 2003 only. Machines from July 2003 onwards require part 1122 020 1211, which is a separate component — not an alternate format of this part number.

What is included in the kit?

The kit includes: 54mm chrome-plated cylinder, matched piston, two piston rings, gudgeon pin, circlips and decompression valve — everything required for a complete top-end rebuild.

What is the bore diameter of this cylinder?

54mm (approximately 2.13"), matching the original factory specification of the STIHL MS660 and 066 engine at 91.6cc displacement.

Is this a chrome or Nikasil cylinder?

This is a genuine STIHL OEM part with a chrome-plated bore — the original factory specification for the MS660/066. Aftermarket alternatives sometimes use Nikasil liners, which have different run-in requirements and characteristics. Always follow the run-in procedure specified in the STIHL service manual when fitting a new cylinder.

How do I confirm my machine's production date?

The production date is encoded in your machine's serial number. Check the data plate on the machine or contact Gustharts with your serial number and we will confirm which cylinder assembly is correct for your saw.

UK Delivery

Fast, reliable delivery from our UK warehouse.

• FREE UK Standard Delivery
  applies to eligible UK orders over £75 ex VAT.
  Estimated delivery: 2–4 working days
  

• UK Standard Delivery from £3.60 + VAT
  Estimated delivery: 2–4 working days

• Next Working Day Delivery – £6.00 + VAT
  
  Order before 3:00pm (Monday–Friday) for next working day delivery
  

All UK orders are dispatched Monday–Friday and sent via a tracked courier service.