I have posted some questions that are very narrow. If they even have an answer, it is one which doesn't really solve the problem.
Shouldn't there be a way to prevent those questions from counting in the accept rate.
I think that an accept rate between 80 and 100% is still acceptable (it has been discussed somewhere on meta). There are some questions I asked on which I can't accept an answer and in the end I still have a pretty good acceptance rate even thought it's not 100%.
Community wiki questions will not count in your accept rate but I think that outside of that there should not be a way to bypass this rate.
If most of your question can't be answered, leading to a very low acceptance rate, you should consider improving your way of asking questions or maybe realize that SO is not the place for such complicated questions.
You could also put a bounty on your question in order to try to get better answers...
If you're asking that many questions that are so narrow that they don't get answers, then perhaps it's a reflection of the question?
You have a 100% percent accept rate on Stack Overflow. What's the issue?
The final question is so abstract that no one could ever provide an answer.