CBR305R Bore Kit

Hello World. I would like to share my CBR305R build, firstly I would like to say. This was the most fun build/project as I have not done anything like this before. I thought a single cylinder with a small engine is a perfect starting point.

Starting Point
I can already hear you all typing or saying.

“Why not get a XXXcc with XXXhp from XXX bike”

. Some answers:

    I love my CBR, its not the quickest but I have had no issues with the bike from the day I picked it up (almost) new with 4kms on the clock, I know exactly what the past 14000km has done, every single fuel up (stored and logged), every service completed by myself. So buying a used bike will not happen.
    I have considered in the past on upgrading to a Daytona 675R (Dream Bike), after factoring the price of the bike and insurance, I figured its not worth it due to my financial status. (Insurance for me on the CBR is currently $480 a year whereas to insure the Daytona will cost me $2600 a year) Maybe down the road I will buy it, but not at the moment.
    Excessive speed and power never seem to appeal to me, in my mind. The quicker you go, the quicker shit happens. Yes its nice to have the power in reserve but I always prefer to ride a slow bike fast rather than a fast bike slow. Given the strict tolerance on speed here in Victoria, Id say only 15% of riding on a ride will have some over the speed limit fun. (Trying to keep a clean record here :) )

But wait, if you say speed never appealed to you why are you doing this modification?

    My reason was that the bike was great fun in the twisties. Just enough power to have fun yet forgiving if you made a mistake. But I have had situations where the lack of power has made several of my overtaking moves (unsafe in my book). Given that there are many roads in the country that has a speed limit of 100, and the top speed of the cbr was 157KPH indicated (130/140? Actual). Overtaking is difficult, some extra power will definitely solve this problem (still not justifiable to get a bigger bike)

The Modifications
What I have here is a Takegawa Bore Up Kit, it changes the engine piston and bore, up from a cast 76mm to a 84mm forged piston. Also increasing the compression ratio from 10.7:1 to 13:1. The kit I bought also comes with a sports camshaft as well as a fuel controller module. Being a japanese made product. Everything was so nicely packaged and protected for shipping.

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(More info on the product HERE)

The taking apart of the bike

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Taking apart the bike was the easy part, every bolt and nut removed was placed into a tray with a small post-it note of where it should go so I will not forget. I thought of doing this job with the engine in the bike. All was well until I realised the exhaust bolts was in the way of the frame. So the engine has to come out.

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A simple 4 bolts and the engine slides right out. (using a car jack underneath to the support the ~30kg engine).

Now that the engine was out, the cylinder and piston was removed

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Comparison with new vs old

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Next up, installing the new cylinder.

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