Do you love your Honda CT125 Hunter Cub? If you do, but you wish that tiny little single cylinder engine packed just a little more of a punch, then you’re in luck. Over the months since the CT125’s introduction, Japanese aftermarket parts specialist Kitaco has come through with a bunch of assorted performance bits—and the latest are two big bore kits to help your Trail Cub realize its full potential. 

Kitaco’s CT125 big bore kits come in two sizes: 164cc and 181cc. The complete kit for each version comes with the cast aluminum cylinder and matching piston in your selected size, an I-map injection controller, an O2 sensor feedback canceller, an oil cooler, and all necessary hardware (including piston rings and gaskets). Additionally, these parts were specifically engineered to fit all existing CT125s. 

If you’re pulling your engine apart anyway, Kitaco also sells a high camshaft and large capacity injector to go along with either of these big bore kits. In previous Kitaco big bore kits, these items were offered as part of the kit—but are now sold separately for the CT125.  

Kitaco Honda CT125 Hunter Cub Big Bore Kit

What’s the cost? The 164cc big bore kit will run you ¥85,800, which is about $626.52 as of December 6, 2022. Bump up to the 181cc kit, and it’s ¥88,000, or about $642.55. Those prices both include tax.  

If you’re located in Japan, you can order Kitaco parts from the company directly, or else purchase them from a number of stores (online and off) that sell their parts. If you’re located outside Japan, parts availability and pricing may vary. However, now that you know that these parts exist, you’ll be better equipped to keep an eye out, if you’re interested in changing things up on your CT125.  

Legislation regarding modification of bikes varies by region, so be sure that you know what the rules are wherever you’re based, ideally before you start making any major modifications to your machine. If you’re unfamiliar with the rules in your country, doing a little extra homework now can save you from a massive headache (and possible heartbreak) later.

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