I'm not sure what the maximum tire size you can put on your bike is, but I know that you can only increase your tire size so much before it actually worsens your stability and handling. Others on here more mechanically inclined will probably be able to give you more info there.
The 3.5 inch rim is not conucive to a tire that is wider than a 140 and wont achieve the propper profile that it was designed for. What will happen is the rim will pull in the sidewalls and "peak the tread" so that you would have a hump in the tire. When riding the bike you will have to work harder to get the bike from side to side over tha hump. Also you will see you wont be able to use the complete tire tread as the bike wont lean over enough affecting the bikes handling. there is also not much room in the swingarm foe a wider tire and will tend to rub.
thank you for all the replies. welll guess im going to go with the stock tire size dont want to mess up the handling. would look cool but not wirth it.
that stinks also i posted some pic's thinking of changing graphics let me know what ya think