Okay, so I bought this bike a a couple years ago and I didn't ride it much but my brother rode it quite alot, I started riding again and when I was riding it, it died on me and wouldnt start back, it doesn’t seem to have much compression, and I need some help diagnosing the problem. Should I get a new top end for it? Or could it be something smaller and less expensive than that
I'll go out on a limb and say you should start with a new top end. You can buy the tool to check compression, or take it to someone that can check it for you, but being a 96, you can bet it needs a refresh.
Looks like Weisco has a piston for your bike but the only one in stock is the 3rd overbore. You will more than likely need to bore the cylinder anyway. It comes with the piston, rings, wrist pin and C-clips for $165. You can look around at other bike part sites. You will also need a new base and head gasket. A local bike shop or automotive machine shop can do the bore job.
I had a 1990 RT180. Nice bike for trail riding. It's air cooled and there is no power valve so doing a top end is pretty easy.