Everywhere I look for parts I will find the a particular are part will fit a 74 76 in fitment section rod strangely the 75 xs650B is almost always missing. For example of the performance carbs from mikes do not include the 75 in the fitment list. I bought them anyway, not knowing there were better things out there, but they are working fine so far. But why? Is there something different, special or bad about the 75 XS650B?