Keihin FCR Carburettor Modifications by JK Tuning & Race Development Remember that, whilst the Keihin FCR Carbs are technically very advanced, they are also mass produced to a budget, and therefore can always be improved on. Take the bellmouths for example, we have a modification that will sharpen throttle response almost right through the entire range. This is a MUST when thinking about any other mods, such as pipe or cam changes. Email us for a free quote or advice. Back to Products & Services Back to Home