Honda ST90 Pit Bike Engine Adapter Kit

Convert your 1973-1975 Honda ST90 to a modern pit bike engine with our Honda ST90 Pit Bike Engine Adapter Kit. Designed for easy bolt-in installation—no welding required. Our 2mm thick adapter brackets ensure durability, we've thrash tested these adapter brackets on a 190cc 5 speed swapped Honda ST90. 

Fits 125cc, 140cc, and 190/212cc and other pit bike engines (minor clearancing may be required). 

Kit includes:

• Two laser cut engine adapter brackets
• All necessary hardware and shims
• Video installation instructions

Notes: Slight clearancing may be required on the adapters for certain engines/transmission configurations. Pit bike style exhaust/foot pegs required.

Photo: Honda ST90 with Zongshen 190cc 5 speed engine installed with thumper exhaust and pit bike foot pegs.