The A.P.E. Stump Puller is the Harley M8 big bore package for riders who want one thing above all else: torque. It takes your Milwaukee-Eight to 124ci, 128ci or 131ci while keeping stock cylinder heads, delivering massive low and mid-range pulling power for touring, two-up riding and highway overtaking.

Taverner Motorsports supplies, installs and dyno tunes the Stump Puller at our Bowen Hills workshop in Brisbane, with Australia-wide shipping.

Harley-Davidson Milwaukee-Eight motorcycle equipped with the A.P.E. Stump Puller Big Bore Kit

What Is the A.P.E. Stump Puller?

The Stump Puller is A.P.E.’s best-value big bore package for riders who want serious performance while retaining stock cylinder heads. Depending on your engine, it can support upgrade paths including 107ci to 124ci, 114ci / 117ci to 128ci, and 131ci options where applicable.
What's included:
  • A.P.E. heavy-duty bolt-on cylinders
  • Forged pistons and gaskets
  • Your choice of CR480, CR483 or CR485 camshaft
  • ⁠Heavy-duty lifters and cam service components
  • ⁠Intake manifold and injectors
  • S&S head bolts
  • Clutch springs
Some 2017 to 2019 M8 models also need the MY20 eight-lobe scavenge oil pump. We'll confirm this when planning your build.
Taverner Motorsports mechanics installing an Alpha Performance Engines Stump Puller kit

Why Riders Choose Stump Puller

  • Huge low-RPM torque and stronger roll-on acceleration
  • Easier overtaking on highways and hills
  • Better touring and two-up performance
  • Keeps your stock cylinder heads
  • Excellent value compared with ported-head packages
Alpha Performance Engines CR480 and CR485 torque-focused camshaft options for Harley M8 engines

Choosing the Right Cam

Your Stump Puller cam choice shapes where the torque arrives. Here's how the three options compare:

CR480 Stump Puller : Maximum low-end torque. Best for heavy touring bikes, two-up riding, and towing.
  • RPM Range: 1,500 to 5,200 RPM
  • Idle: Smooth / Subtle Rumble
  • Suits: Heavy Touring models, 2-up riding, and 124ci, 128ci & 131ci M8 torque builds
CR483 Stump Puller : Balanced torque and rideability. Best for riders who want strong pull with a smoother everyday feel.
  • RPM Range: 2,000 to 5,500 RPM
  • Idle: Mild / Strong Rumble
  • Suits: Daily street riders and touring bikes seeking a broad, early-starting torque curve
CR485 Stump Puller : Strongest performance feel. Best for riders wanting the most aggressive Stump Puller while keeping good street manners.
  • RPM Range: 2,500 to 6,500 RPM
  • Idle: Aggressive / Choppy
  • Suits: Aggressive street riders and big bore builds chasing maximum torque output
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Harley-Davidson touring motorcycle utilizing the low-end torque of an A.P.E. Stump Puller kit

Who Is It Best For?

  • Road Glide riders.
  • Street Glide riders.
  • Road King riders.
  • Ultra and touring riders.
  • Fat Boy, Breakout and Softail riders wanting torque.
  • Riders who carry passengers or luggage.
  • Riders who want huge performance without a full race-style build.
Black custom motorcycle with chrome engine parts and dual exhaust pipes against wooden background.

Stump Puller Specs and Price Guide

Capacity Suits Cam Options Claimed Output Price From
124ci Factory 107ci M8 base engines CR480, CR483, CR485 Stump Puller Up to ~140 HP / 150 ft-lbs From $4,190 AUD Parts
128ci Factory 114ci & 117ci M8 base engines CR480, CR483, CR485 Stump Puller Up to ~145 HP / 155 ft-lbs From $4,190 AUD Parts
131ci Factory 114ci, 117ci & 121ci M8 base engines CR480, CR483, CR485 Stump Puller Up to ~150 HP / 160 ft-lbs From $4,190 AUD Parts
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Stump Puller Installation and Dyno Tuning in Brisbane

Our Bowen Hills workshop handles the full Stump Puller build, from teardown and cylinder fitment to cam install and a dyno tune matched to your exhaust and intake. Every job is covered by Taverner Motorsports' workshop warranty and full after-sales support. Interstate riders can ship their bike directly to our Brisbane workshop or buy the kit online with Australia-wide shipping for local fitment.
Feature A.P.E. Power Plus Cam Kit A.P.E. Stump Puller
Upgrade Type Stage 2 Cam Upgrade (Stock Displacement) Big Bore Kit (124ci / 128ci / 131ci)
Primary Focus Throttle response & mid-range acceleration Low-end & mid-range pulling torque
Cam Options CR480, CR483, CR484, CR485 & newer profiles CR480, CR483, CR485 (Retains stock heads)
Best For First performance upgrade; Stage 2 feel without a full engine build Touring models, heavy bikes, two-up riding, and effortless highway overtaking
Main Benefit Sharper acceleration, stronger Harley feel, and improved rideability Huge low-RPM pulling power and effortless roll-on torque
A.P.E. Stump Puller 124ci and 128ci Big Bore Kit components including cylinders, pistons, and cam

Why Choose Taverner Motorsports for Your Stump Puller Build?

A big bore build is only as good as the planning behind it. We match your capacity, cam, exhaust and intake to how you ride, check model-specific requirements like the MY20 oil pump, and tune every build on our own dyno. As an authorised Alpha Performance Engines specialist and installer, we've completed hundreds of A.P.E. builds for riders across Australia.
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FAQs

Some of our most commonly asked questions are answered here. For other queries please contact us directly, so our team can assist you.

Is the Stump Puller good for touring bikes?

Can I keep my stock cylinder heads?

How much does a Stump Puller cost in Brisbane?

How much torque does a Stump Puller make?

Do 2017-2019 M8 models need extra parts?

Does the Stump Puller need dyno tuning?

Which Harley models suit the Stump Puller?

Book an A.P.E. STUMP PULLER build consultation in Bowen Hills today

  • Monday: 10:00am – 6pm
  • Tuesday: 10:00am – 6pm
  • Wednesday: 10:00am – 6pm
  • Thursday: 10:00am – 6pm
  • Friday: 10:00am – 6pm
  • Saturday: Closed
  • Sunday: Closed
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