Honda CRF150R 2020 Owner's Manual & Competition Handbook page 71

Piston/Piston Pin/Piston Ring Inspection
We recommend you consult the Service Manual or
your dealer for correct Service Limit
measurements.
Piston Ring Installation
1. Remove the carbon deposits from the piston
crown and piston ring grooves with the
removed ring (1).
(1) removed ring
2. Apply engine oil to piston rings and install
them.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
Do not damage the piston during piston ring
installation.
• To install the oil ring, install the spacer first,
then install the side rails.
• Install the top ring on the piston with the
marking side facing up.
3. After installing the rings they should rotate
freely, without sticking.
Space the ring end gaps 180 degrees apart
between top ring and upper side rail.
Space the ring end gaps 90 degrees apart
between upper side rail, spacer and lower side
rail.
Piston/Piston Rings/Piston Pin
(1)
mark
top ring
oil ring
top ring
side rail
oil
spacer
ring
side rail
65
Servicing Your Honda