CBR 250/300cc ENGINE SWAP INFORMATION
Deep diving into all the information about doing a 250/300cc engine swap can be daunting and overwhelming but here is a quick little run down of it all so that you have all the information you could possibly need before diving into it.
OKAY! Straight up - A full engine swap conversion on your Grom will cost $3500 minimum. That’s not including the price of your Grom and depending on the parts you choose to buy, it can easily exceed over that price range pretty quickly!
There are 3 main components for when you are doing a 250/300cc engine swap!
1ST: You will need an engine package!
Either a CBR250, CBR300 or CB300F.
Apart from the engine displacement cc, the only difference is that the CBR250 and CBR300 engines are black, while the CB300F engines come in silver or gold. The CB300F engines also use the same style speedo as the Grom so it saves you the hassle of doing any modifications / buying any adapters for the conversion.
Either a CBR250, CBR300 or CB300F.
Apart from the engine displacement cc, the only difference is that the CBR250 and CBR300 engines are black, while the CB300F engines come in silver or gold. The CB300F engines also use the same style speedo as the Grom so it saves you the hassle of doing any modifications / buying any adapters for the conversion.
2ND: You will need a swap kit.
The swap kit contains both the engine bracket and 3D printed fuel injector relocation elbow needed for the conversion as well as all the other little bits and pieces required for the engine swap.
The swap kit contains both the engine bracket and 3D printed fuel injector relocation elbow needed for the conversion as well as all the other little bits and pieces required for the engine swap.
3RD: You will need an aRacer ECU kit to make the bike / engine run properly! The bike will start and run using the OEM ECU from the CBR but it won’t be rideable. There are other ECU options out there like the Power Commander but aRacer is the popular choice for this engine swap and if you were to do a price comparison with ECU’s and AutoTune modules, they all come in at around the same price range.
Once you have those 3 components, it’s then just a matter of modifying the CBR wiring harness, radiator and exhaust header to suit the Grom. Alternatively you can purchase one of our custom made radiators and titanium exhaust systems to save yourself the time and hassle.
These bikes can also be fully engineered with the 250/300cc engines but unfortunately it means your Grom is no longer LAMS approved.
Depending on what state you live in, you will have to find an engineer local to you for pricing and to find out your states requirements. I am Brisbane based and my engineer charges $500. Just to give you a rough ball park figure.