Piston Rings (Std / 0.5 mm / 1.0 mm OS) | Honda CB550K / CB550F

Part: Piston Rings (Standard / 0.5 mm over size / 1.0 mm over size) for Honda CB550K / CB550F – Sold Individually

Why You Need This: The Honda CB550K / CB550F engines are pretty tough machines, we have heard stories of bikes with 100K miles on them that keep on trucking. However engines need to be freshened up as oil leaks happen and compression drops. If you cylinder bores check within the service limits then a light hone with a fresh set of piston rings will get your Honda CB550K / CB550F back to factory spec and on the road. However, if the cylinders measure outside the service limit,  they will need to be bored oversize. This will require you to install new oversize pistons and matching oversize piston rings along with a new wrist pin and retaining clips. 

Piston Ring kits are offered in three different sizes for the CB350 family of engines:

• Standard (58.5 mm bore)

• 0.5 mm Over Size

• 1.0 mm Over Size

Our standard piston ring kits are designed to fit the factory Honda pistons in standard size (58.5 mm) used in the Honda Honda CB550K / CB550F engines. 

Oversize piston ring kits are available in 0.5 mm and 1.00 mm oversize, designed to fit factory Honda oversize pistons as well as our very own "Pulsar" series oversize pistons. 

Our modern piston rings are designed to improve sealing, ease of installation and ensure long service life.

Each piston ring set includes: 

• A gas nitride coated forged steel top ring (silver). This is a hard coating on all surfaces of the ring which gives it increased wear resistance and a lower coefficient of friction on the cylinder walls. 

• Steel phosphate 2nd ring (black). 

• An easy-to-install modern nitride three piece oil ring, which makes installation onto the piston and cylinder assembly a LOT easier than the old style brittle cast iron one piece oil rings. 

Piston ring sets are sold individually, one set per piston, you will need four sets per engine. We recommend getting a fresh set of wrist pins and clips along with an overhaul gasket kit to get the rebuild done right. 

Each set includes:

• Top ring (Silver Face)

• Second Ring (Black)

• 3 piece Oil Ring (wavy + 2 rails)

Note: These piston rings will NOT FIT CB500K 4 cylinder engines.

Installation Tip: Cylinders must be measured and checked for taper, roundness and top ridge, you will need a micrometer and either the telescoping gauges or dial bore gauge to complete this. If everything measures out then the cylinders must be cleaned up with a cylinder hone to accept new rings. We always recommend to double check machine work. Top and second rings are identical and installed with the "top" marking or beveled edge of the rings facing up towards the crown of the piston. Oil ring is installed with the wavy ring first, then sandwiched with the thin rails top and bottom. Make sure to check the piston ring end gap on the compression rings prior to installation. Minimum gap is 0.012" (.3 mm) and maxim gap is 0.030" (.5 mm). Rotate the open ends of all the rings 180 deg apart from one another once on the piston. Oil rings and cylinders well prior to installation.