Jay: My 2001 200MXC is 14/48. Regardless, I best Sharla would benefit from bumping up a couple of teeth on the rear.
Sharla: I'm not trying to talk around you, rather answer the questions raised. Kathy is correct, if you can see half of your sprocket (assuming proper tension) it is time to change the chain. Jay is correct as well. You can change the chain without changing the sprockets (assuming you catch it in time).
I moved from 14/50 to 13/52 on my 400 and it made a WORLD of difference.
My 200 is capable of lifting the front end in 2nd, 3rd or 4th, often breaks loose in 2nd and usually breaks loose in 1st. Raising the final ratio has the effect of tightening up the gear spread (if I remember correctly) and therefore you will rev out faster and have to shift more often. Additionally, your top speed will be lower. You tend to put more power to the ground so you will benefit from short shifting the bike and staying in the lower portion of the power band as apposed to always running wide open.
I haven't looked into changing the final ratio of my 200 as I am much more comfortable with the power characteristics of a 2 stroke. We will see once I have the 200 dialed into my riding characteristics.