I am looking for a new carb to improve hp on my old 200sx, i have looked everywhere but cant find anything. I would appreciate any information on what kind or where i can find one for it. Is it true a 200x carb will fit? thanx...

 

Here is a little trick I happened onto a couple of years ago. I have a '78 Honda XL100 dirtbike, which are pretty easy to find in junkyards. It was acting up and I thought it was the carb. I also had a 200es 3-wheeler (it used the same carb as your sx). I noticed that the carb bodies looked the same. I installed the XL's carb on the 200 and it came alive!!! That worn out 200es would pull third gear wheelies. It ran great, especially on low-mid. Upon further inspection, I found that the pilot jet is larger in the XL's, the dump tube is larger, and the jets are brass and easier to find. I used the cap and needle off of the 200, but you might notice even more power if you use the needle for the XL.
This will be cheaper than any aftermarket carb. You should be able to pick one up for $25-50.