Yes, These 05 and up stock Superjet carbs are not easy to adjust the mixture screws. I have to charge $150 just to take them completely all apart, mill out the plugs, then remove them, then mill down the housings so I can solder on some 'T's for adjusters and then wash, clean, Re-jet and re-assemble complete. But, it is a much cheaper way until you upgrade to the much more expensive AFTERMARKET dual carbs!