So, about 6-7 years ago I bought a z50 from my little brothers friend for $50. He had had it running for a year or two and it had duct-tape as tire tread. The Plug wire was bad, fixed it and it started right up. Replaced the tires and went to ripping. We rode it pretty hard for several weeks, had a riot on it. It became our "pitstop" bike when we were at the dunes. We would cruise it over to the toilet and at lunch we would set up a little track in the parking lot to race around. Ran pretty good for a year or two then became hard to start. We would drag it around the parking lot and sometimes it would start up and run great, other times it wouldn't start at all. Every now and then I can give it a kick and it will start up and run but mostly it won't start. It seems to have very little compression, very easy to kick compared to our 05 crf50. The z50 was a blast and actually would hang or beat the 05 on the sand (advantage wider tire I think). Anyway, is this thing worth fixing? What is a new top end going to run me?