1 9

Rolling Wrench

GY6 Stage 2 Engine Package - 172cc - Carbureted

GY6 Stage 2 Engine Package - 172cc - Carbureted

$655.00 USD
$655.00 USD
Sale Sold out
Shipping calculated at checkout.

Stage 2 takes everything that works in Stage 1 — the reliable 172cc big-bore foundation — and unlocks its full potential with a properly tuned PWK 28mm carburetor setup. If your scooter feels sluggish off the line, inconsistent at throttle, or just isn’t pulling like it should, Stage 2 fixes that. The fueling becomes crisp, throttle response sharpens, and power delivery becomes smooth and predictable. No guesswork. No part hunting. Just bolt on and ride.

The Details

This kit is a direct fit for all QMJ157 engines — the most common GY6 variant found in scooters and swap builds. No machining. No case boring. Just install and ride.

Why Stage 2?

The 172cc big-bore top end makes power — but only if the engine can breathe. The PWK 28mm carburetor is specifically matched to the valve and port design of this cylinder head, unlocking that power cleanly and reliably.

Carburetor System (All Variants Include):

  • 5-Axis CNC Intake Manifold + High-temp silicone intake hose
  • 76" Throttle cable (pre-installed) — no adjusting or trimming
  • 20-piece jet kit for altitude + exhaust tuning
  • Made in USA UNI Pod Filter — washable + reusable
  • Clocking / leveling flange for perfect angle and clearance

Carb Finish Options (Same Performance, Different Look):

  • Natural — clean OEM+ mechanical look
  • Polished — mirror-finish showpiece
  • Black — stealth and minimal
  • Pro — upgraded finish + aesthetic detailing

Choose Your Piston Kit

Full ProBld (Forged) — strongest, coolest-running, best long-term reliability.

  • 4032 forged piston — high strength with daily reliability
  • Rings pre-measured and installed for you
  • Big-valve ProBld head + full hardware
  • ProBld performance camshaft

Full NCY (Cast) — cost-effective daily setup.

  • Cast piston — reliable for daily street use
  • Rings installed by you
  • NCY camshaft tuned for torque

If you want the toughest, longest-lasting build → Go ProBld.
If you’re building on a budget → NCY gets the job done.

Important Things to Note

You must verify that your engine code is QMJ157. (CLICK HERE) to learn how to check.

Buggy / go-kart owners: Some frames use alternate stud spacing. Confirm before installing.

View full details