Sadun L., Segert J. Constructing Non-Self-Dual Yang-Mills Connections on $S^4$ with Arbitrary Chern Number (25K, AmsTeX 2.0) ABSTRACT. We prove the existence of non-self-dual Yang-Mills connections on $SU(2)$ bundles over the standard four-sphere, and discuss how such connections may be constructed. This construction produces connections on all bundles with second Chern number not equal to $\pm 1$.