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Rolling Wrench

GY6 Stage 3 Engine Package - 172cc - Carbureted

GY6 Stage 3 Engine Package - 172cc - Carbureted

$1,280.00 USD
$1,280.00 USD
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Shipping calculated at checkout.
Want to upgrade to fuel injection instead? 👉  Click here!

Stage 3 (carbureted) finishes the package — air → fuel → exhaust. You’re getting a proven 172cc top end, a properly matched PWK 28 mm carb, and your choice of performance exhaust. The result is crisp throttle response, smoother mid-range, and real-world power you can actually feel — without getting lost in a tuning rabbit hole. Choose your combo: Full ProBld (Forged) or Full NCY (Cast) plus four carb finishes and four exhaust styles (32 total configurations).

The Details

This Stage 3 kit is a true drop-in package for QMJ157 GY6 engines and is the largest big-bore setup you can run without case boring. Paired with a PWK 28 mm carburetor and a properly flowing exhaust, you’re looking at roughly ~13 HP (vs. ~7 HP stock) with clean fueling across the rev range and strong reliability. No oil cooler required, no weird mix-and-match parts — everything is chosen to work together.

Pick Your Top-End Package

Full ProBld (Forged) — strongest + longest-lasting:

  • 4032 forged piston for hard riding and long-term reliability
  • Piston rings pre-measured & installed in the cylinder (no guesswork)
  • ProBld big-valve head (28 mm intake / 23 mm exhaust) with all hardware + NGK plug
  • ProBld performance camshaft (strong low-to-mid punch that keeps pulling up top)
  • 5-axis CNC clocking/leveling flange (port-matched ~27.5 mm)

Full NCY (Cast) — value-minded daily setup:

  • Cast piston — solid choice for commuting and everyday riding
  • Rings installed by you (great if you like to double-check your own build)
  • NCY head (28 mm / 23 mm) with hardware + NGK plug
  • NCY camshaft focused on low-end torque and rideability
  • Clocking flange included for clean, repeatable fitment

PWK 28 mm Carburetors — 4 Styles (Same Performance)

Every carb option is pre-assembled and test-fit in-house with all the supporting pieces you actually need:

  • 5-axis CNC intake manifold + high-temp silicone hose (won’t dry rot like cheap rubber)
  • 76" throttle cable (pre-installed on the carb)
  • 20-piece jet kit for dialing in altitude and setup
  • Made in USA UNI pod filter (washable / reusable)
  • Clocking/leveling flange for perfect carb angle and frame clearance

Same performance, different look — pick the style that matches your build:

  • Natural — clean raw finish
  • Polished — mirror-shine show finish
  • Black — stealthy and tucked into the frame
  • Pro — premium detailing and finish

Exhaust Selection — 4 Options

Choose the sound and style that fits your build. All options flow way better than stock and are matched to the 28 mm PWK:

  • ProBld Stealth Carbon Fiber — low-key carbon look with a tight, refined tone. (CLICK HERE)
  • ProBld Carbon Fiber Weave — visible weave canister, lightweight with a crisp note. (CLICK HERE)
  • Yoshimura RS-2 Carbon — iconic Yoshi performance with a deep, premium sound. (CLICK HERE)
  • Yoshimura Raw Aluminum — lightweight raw can with classic Yoshi tone. (CLICK HERE)

By Stage 3, intake, fueling, and exhaust are working as a matched system. The result is predictable tuning, smoother power delivery, and a GY6 that finally feels “finished.”

Important Things to Note

  • Engine fitment is critical. This kit is designed specifically for QMJ157 GY6 engines. If your engine code is not QMJ157, this kit will not fit. CLICK HERE to learn how to decode your engine.
  • Buggy / Go-Kart owners: there are a lot of GY6 variations in buggies and go-karts. We have not tested every single one, and some may require case boring or may have different stud spacing.
  • Many buggy owners first buy an inexpensive top-end test kit to confirm everything before committing to a full build: CLICK HERE for the GY6 61mm Test Gasket Kit.

If you’re unsure about your engine, combo, or parts selection, reach out first — it’s way easier to confirm up front than to fix a mismatch later.

What's Included

  • 172 cc Cylinder Kit (Cylinder, Piston, Rings, Wrist Pin, Clips, Base Gasket, Head Gasket)
  • Big-valve performance head (28 mm intake / 23 mm exhaust)
  • Performance camshaft (ProBld or NCY depending on kit)
  • NGK spark plug + full mounting hardware (intake & exhaust studs, gaskets, nuts)
  • 5-axis CNC clocking / leveling flange (port-matched ~27.5 mm)
  • PWK 28 mm carburetor (Natural / Polished / Black / Pro)
  • 5-axis CNC intake manifold + high-temp silicone intake hose
  • 76" throttle cable (pre-installed on the carb)
  • 20-piece jet kit
  • Made in USA UNI pod filter
  • One (1) performance exhaust of your choice

Everything is chosen to work together — no chasing random parts or guessing what fits.

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