Why wont my dirt bike kick into first gear?

I have a honda 50 cc dirt bike and when i kick it into first gear it doesn't make the normal sound it usually does and something feels different when i do it but when i kick it back into neutral everything feels like its back to normal. Any answers on what could possibly be wrong? and how to fix this.

i sometimes have that problem. You have to give a VERY solid kick when you are shifting up to first or down. if not you will be almost in first, but the gears will be grinding. Also, dont really force it too much because you could bend a shift fork.