KTM 85 SX Engine Packages
Transparent KTM 85 SX mod packages from HP Race Development: Weekend Racer, Privateer, and Factory Works builds with race porting, GET CDI mapping, billet head options, and complete engine services.
Select Your Level
Choose the package first. The engineering notes and build justification follow below for families who want the deeper breakdown.
KTM 85 SX Platform
85cc PlatformWeekend Racer
Competes head-to-head with national mod kits without the fluff or unneeded extras.
$650 starting
Pricing may vary based on condition of parts received.
What You Ship Us
Cylinder with powervalve and carb
Includes
- Race Porting
- Carb Bore & Setup
- Head available as an add-on
- Piston & Gasket Kit available upon request
Recommended For
Local racing, practice bikes, and families who want real KTM 85 performance without overbuying.
Pricing may vary based on condition of parts received.
Privateer
Our most popular KTM 85 upgrade: the full synergistic port, ignition, carb, and head system.
$1,850
Pricing may vary based on condition of parts received.
What You Ship Us
Cylinder with powervalve and carb
Includes
- HP Race Porting Spec
- HP Custom Mapped GET CDI
- Carb Bored & Set Up with Notes
- Billet Head with HP Custom Race Dome
- Piston Kit
- Top End Gasket Kit
Available Add-ons
- +Professional installation onto customer's engine: +$150
Recommended For
Regional championships, serious amateur racing, and the best value KTM 85 mod package.
Pricing may vary based on condition of parts received.
Factory Works
Zero compromises: complete top and bottom end build, professionally assembled and verified.
$3,950 / $4,600 with dyno
Pricing may vary based on condition of parts received.
What You Ship Us
Complete engine
Includes
- Factory Works Porting
- Custom HP Mapped GET CDI
- Carb Bored & Set Up with Notes
- Billet Head with HP Custom Race Dome
- Piston Kit
- Top End Gasket Kit
- Billet Connecting Rod
- REM / Super Finished Internals
- Ceramic Bearings for durability and reliability
- Cerakoted Cases available upon request
- Dyno Test & Power Verification available: +$650
Available Add-ons
- +Vapor Blast & Inspect Engine Parts for used engines: +$250
- +Replace all wear parts: priced after inspection
Recommended For
Loretta Lynn's, Mini Os, national-level KTM 85 and Supermini programs.
New engine pricing shown. Used engine costs extra after inspection.
The Stock Bottleneck
"Most KTM 85 mod packages are priced like full national builds but still miss the way port work, ignition, head volume, and carb setup need to work together."
The HP Race Dev Solution
"We match the porting, GET CDI map, carb bore, head, and fuel setup as one engineered system so the bike accelerates, not just revs."
We don't just "grind ports." We mathematically correct the engine's geometry to solve this specific flaw.
Engineering the KTM 85 SX Platform
The KTM 85 responds best when the cylinder, powervalve, carb signal, and ignition curve are treated as one package. A port-only build can move the power higher, but without matching the CDI curve and head spec, the rider often gets a narrow engine that is harder to keep driving out of corners.
Our Privateer and Factory Works packages are built around synergy: port timing, combustion chamber shape, carb bore, and GET CDI mapping are aligned so the engine makes usable torque and keeps pulling up top. That is the difference between a bike that sounds fast and a bike that actually gets to the next jump face sooner.
For Factory Works engines, durability matters as much as peak output. REM finished internals, ceramic bearing options, billet rod hardware, and dyno verification are used to make a national-level engine that can survive real moto length rather than a short dyno pull.
Parts For This Platform
Common products used with KTM 85 SX package builds.
KTM 85 Stage 2 Mod Package
$1,849.95Direct product listing for the core KTM 85 Stage 2 package.
View ProductGET CDI KTM SX85 2018-2024
$582.95High-performance GET ignition for 2018-2024 KTM 85 SX.
View ProductGET CDI KTM 85 SX 2025-2027
$582.95GET ignition option for the latest KTM 85 SX platform.
View ProductVertex OEM Replica A Piston Kit - 85 KTM Group
$114.95Service piston option for KTM, Husqvarna, and GasGas 85s.
View ProductBillet Connecting Rod Rebuild Kit KTM SX 85
$399.95Billet rod upgrade for KTM 85 bottom-end rebuilds.
View ProductKTM Husky GasGas 85 Full Engine Gasket and Seal Kit
$216.95Full gasket and seal kit for complete 85 engine service.
View ProductCommon Questions: KTM 85 SX Platform
What is the difference between a Mod 85 and a Supermini build?
A Mod 85 retains stock displacement but maximizes efficiency. A Supermini often involves boring and stroking, which requires completely different port timing to handle the increased piston speed.
How often do I need to do top ends on a Factory Spec 85?
High-performance engines demand maintenance. We recommend rings every 10-15 hours for peak competition, though our balanced cranks significantly reduce wear on the bottom end.