The world of minimotos (especially the Honda Grom and Ruckus) are full of some crazy builds, and over the years one of the wildest things I’ve seen is a motor swap from the Honda CB300R thanks to companies like Chimera Engineering that make kits. Here’s one that’s already had the swap done for you – the seller claims it’s good for 90 miles per hour! Have fun with that on 12″ wheels…
The stock 125cc motor in the Grom is rated at 9 horsepower. The CB300’s parallel twin puts out 30.5! To do this swap you don’t just need the engine – you also need the radiator, radiator fan, throttle body, wiring harness, other harnesses, ECU, handlebar controls, ignition boot, and more – that’s why people typically just buy an entire donor bike instead of just the bigger motor.
In addition to the engine swap, this example has an ARacer ECU, bigger chain conversion, ProTaper handlebars, rearsets, and a WickedGrom starter conversion adapter kit. The seller bought the bike new and says it has 450 miles on it but it’s unclear how many of those are post engine swap.
Find this Grom for sale for $6,000 in Northeast Maryland here on Facebook Marketplace.