I'm afraid that you can't talk about Norwegians in general...
In written Norwegian, Nynorsk requires three genders while Bokmål allows two. In spoken Norwegian, dialects close to Nynorsk use three genders, while only the Bergen dialect uses a pure two-gender system. You will also find something close to a two-gender system in Western Oslo, and maybe some other wealthy neighbourhoods in the largest cities.
The rest of us, including myself, aren't consistent. Some people use three genders when they speak and two when they write. Some mainly use the feminine declension for the definite article, not for the indefinite (for exampel en bok - boka). There is also variation between different words from the feminine noun class. The masculine declension indeed sounds unnatural (unless you speak the Bergen dialect) for some words, such as øy, jente and ku. It is different for many other feminine words.
I know this must be totally confusing for people who try to learn Norwegian - but that's how it is!