Yes! Now that the bore is bigger than before, the power valve (if there is one) needs to be modified so that no part of it extends into the bore under any throttle conditions or whether the engine is either at room temperature or operating temperature. This is ALWAYS the responsibility of the engine builder. We will not accept any liability if this work has not been done properly.
Next, the cylinder head may need to be machined to suit the new bore diameter and piston shape. If this is not done correctly, there could be a reduction in performance or, in some circumstances, major engine damage may result.
Also, with a bigger bore you will now be burning extra fuel AND extra air, so it may be necessary to adjust the fuel/air mixture to suit the bigger capacity engine. Of course, that extra fuel and air needs to go out of the exhaust system after it has been burned in the engine, so that might need modification too.
Another thing that is sometimes necessary is to alter the ignition timing to suit the bigger engine. As always, incorrect mixture and/or incorrect ignition timing can lead to severe detonation.
With all of the above, and with any aspect of increasing engine capacity or performance, it is something that demands the skill, knowledge and expertise of a professional engine builder to be confident that the conversion will work as intended.