"Pulsar" Piston Kit | Honda CT90 / Trail 90

Part

"Pulsar" Series Piston Kit for Honda CT90 - "Trail 90" Motorcycles

Why You Need This

After countless miles of adventure, your vintage Honda CT90 might be in need of an engine rebuild. When that time comes, the cylinder must be measured to see if it is still within factory spec for a simple hone and re-ring or is it worn beyond factory limits, necessitating an oversize bore. This requires a new oversize piston to match a freshly bored cylinder bore, along with matching piston rings, a new wrist pin and retaining clips.

Original Honda oversized pistons and rings for the Trail 90 are long out of production and incredibly hard to find. No reason for worry, here at Common Motor, we have developed our own line of standard and oversize piston kits specifically for the Honda CT90.  The"Pulsar" series pistons are inspired by the original Honda ART cast aluminum design, now upgraded with modern manufacturing techniques and performance enhancements.

Built for reliability, performance and a second life on the trail:

• Each "Pulsar" piston is made from pressure cast aluminum and CNC finished machined.
• Piston skirts feature a MoS2 (molybdenum disulfide) dry film lubricant anti-friction coating applied to the aluminum surface to reduce wear and scuffing.
• Piston crown and the top ring groove have a high temperature hard anodization applied to the surfaces to increase overall piston durability and thermal transfer (important in an air cooled engine), as well as preventing the top ring from micro welding (aka getting "stuck") into the ring groove.

Speaking of rings, the "Pulsar" series pistons include modern piston rings to improve sealing, ease of installation and ensure a long service life. Each ring set includes:

• Gas nitride coated forged steel top ring (silver) - this is a hard coating on all surfaces of the ring that gives increased wear resistance and lower coefficient of friction on the cylinder walls.
• Steel phosphate coated 2nd ring (black).
• Modern gas nitride three piece oil ring, which makes installation on to the piston and cylinder assembly a LOT easier than the old style cast iron one piece oil rings did.

Additionally, the "Pulsar" series piston kits also include new writs pins (gudgeon pin) and the proper "C" style retaining clips for correct fit with minimal pin slop.

"Pulsar" series Pistons for the Honda Trail 90 are available in the the following options:

• Standard (no oversize) - #4331
• 0.5 mm Oversize - #4332
• 1.0 mm Oversize - #4333