Picked up some Keihin jets from the dealer and am about to tear open my carb but upon looking at the jets I have and looking at pics on the web and in my exploded carb pic I notice that my main jet is quite a bit longer than the one that appears to be in there(1/2" compared to what appears to 1/4" in the pics). Do I have the wrong jet? Or do I just put that big ole sucker in the needle jet holder and go for it? It's a 160 if that matters. Thanks.