At BP Racing ATV we will accept returns within 30 days for almost any part that is new, unopened, never installed, in the original packaging. We ALWAYS STRONGLY recommend that these parts be assembled and tuned by a qualified mechanic with experience working on these types of engines. Warranty does not cover any part(s) failure that is a result of improper installation, improper tuning, improper break in, or misuse. For any warranty to be considered the part(s) in question must first be sent to us and possibly the manufacturer for inspection. We can not warranty parts based on photos or phone calls alone.