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ProX

ProX Engine Rebuild Kit

From $1,110.95

Complete rotating and reciprocating rebuild kit including crankshaft assembly, main bearings and seals, pistons and components, and a complete engine gasket kit All components were developed through extensive research and development on ProX’s in-house engine dyno Crankshafts come completely assembled using Maxima® assembly lube and are inspected in-house for proper dimensions and trueness Connecting rods feature proprietary design done in-house, and are forged, heat-treated, and shot-peened for ultimate tensile strength and reduced stress risers Connecting rods include graded bearings in the big end to ensure proper clearance, as well as a bronze bushing in the small end, both improving longevity and performance Pistons are cast from OEM-grade alloy and feature MOS2 skirt coating and hard- anodized crown and ring grooves for improved performance and wear resistance through reduced friction and improved heat resistance Includes Japanese-sourced, Koyo main bearings along with OEM quality seals and complete gasket kit to ensure a reliable engine rebuild More applications covered in fewer part numbers with versatile gasket kits and compression ratios Available in A/B/C graded bore sizes

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Product description

Complete rotating and reciprocating rebuild kit including crankshaft assembly, main bearings and seals, pistons and components, and a complete engine gasket kit All components were developed through extensive research and development on ProX’s in-house engine dyno Crankshafts come completely assembled using Maxima® assembly lube and are inspected in-house for proper dimensions and trueness Connecting rods feature proprietary design done in-house, and are forged, heat-treated, and shot-peened for ultimate tensile strength and reduced stress risers Connecting rods include graded bearings in the big end to ensure proper clearance, as well as a bronze bushing in the small end, both improving longevity and performance Pistons are cast from OEM-grade alloy and feature MOS2 skirt coating and hard- anodized crown and ring grooves for improved performance and wear resistance through reduced friction and improved heat resistance Includes Japanese-sourced, Koyo main bearings along with OEM quality seals and complete gasket kit to ensure a reliable engine rebuild More applications covered in fewer part numbers with versatile gasket kits and compression ratios Available in A/B/C graded bore sizes

Features

  • Complete rotating and reciprocating rebuild kit including crankshaft assembly, main bearings and seals, pistons and components, and a complete engine gasket kit
  • All components were developed through extensive research and development on ProX’s in-house engine dyno
  • Crankshafts come completely assembled using Maxima® assembly lube and are inspected in-house for proper dimensions and trueness
  • Connecting rods feature proprietary design done in-house, and are forged, heat-treated, and shot-peened for ultimate tensile strength and reduced stress risers
  • Connecting rods include graded bearings in the big end to ensure proper clearance, as well as a bronze bushing in the small end, both improving longevity and performance
  • Pistons are cast from OEM-grade alloy and feature MOS2 skirt coating and hard- anodized crown and ring grooves for improved performance and wear resistance through reduced friction and improved heat resistance
  • Includes Japanese-sourced, Koyo main bearings along with OEM quality seals and complete gasket kit to ensure a reliable engine rebuild
  • More applications covered in fewer part numbers with versatile gasket kits and compression ratios
  • Available in A/B/C graded bore sizes

Specifications

Select your options to see the exact item’s specifications.

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What Our Customers Say

5 out of 5 based on 247 reviews
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“Great place to buy from great parts great people”

Sam Miller · Mar 2026

“10/10 experience with Empire Cycle. Kristin and Joe are great to work with and very helpful. Will absolutely do business with them again.”

Wesley Schmidt · Jan 2026

“I had a pleasant experience doing my business with these folks! I purchased a 2024 CF MOTO 450SS. They communicate with you well, care about what your needs are, and prioritize your satisfaction. I also took my another bike for mods. Austin and Amy do an amazing job! Thank you, everyone!!”

Edward Kim · Jan 2026

“Amazing people!! Helped me out with parts when I was in a pinch and they were very friendly. I would recommend anyone looking for moto supplies or new vehicles to stop in and see what they got.”

Kyle Glubrecht · Jan 2026

“Awesome people and great deal on gear! Outfitted the whole family and several friends with the insane Helmet deals. Keep it up 🙏”

Christopher Davis · Jan 2026

“:) Thank you”

Lara M · Jan 2026