Ultimate Honda Grom Engine Swaps: CBR300 vs Ninja 400!

Dropping a bigger engine into a Honda Grom or Kawasaki Z125 changes everything. In this episode of Road Dirt, Mike Boyd goes deep into the small-bore motorcycle community to check out wild engine swaps— from single-cylinder CB300 conversions to twin-cylinder Ninja 400 and 500cc monsters. We sit down with custom builders Josh and TJ from "Grom Swap the World" to break down custom frame modifications, solving fuel injection issues, and why upgrading to 13-inch tires is a must if you want to safely cruise at 85+ mph on the highway. This Road Dirt presentation is brought to you by Law Tigers, motorcycle lawyers. Find your local motorcycle legal experts at https://lawtigers.com For Mike's story and photos, click here: https://roaddirt.tv/small-bore-mania-... Follow Grom Swap the World on Instagram & Facebook! TIMESTAMPS: 0:00 - Introduction to Small-Bore Engine Swaps 0:20 - The Honda CBR300R Grom Swap (Pros & Cons) 1:10 - How to Modify a Grom Frame for a 300cc Engine 2:25 - Keeping It Stable on the Tail of the Dragon 3:15 - Beyond 300cc: Twin-Cylinder Ninja 400 Swaps 4:12 - Fixing the Idle and ECU Dead Spots 5:05 - Why 12-inch Tires Fail at 100 MPH (13-inch Upgrades) 6:10 - Wrap Up & Where to Find the Builders #HondaGrom #GromSwap #MiniBike #Ninja400 #CBR300 #Motorcycle #RoadDirt #LawTigers #GromLife #CustomMotorcycle