I have a mac titan 57 that runs but won't stay running. It used to be my Dad's. He said it was a hell of a saw. Is it worth the effort of tracking down parts to fix it? It has a new bar, multiple chains, a new pull starter and a new clutch and sprocket. It quit some years ago and I finally talked my Dad out of it. I think it needs a carb rebuild and possilbly seals. The rpms change when you lay it on it's side and then it dies.