Sounds like the timing's retarded. Check the timing, it needs to be at around 8-12 degrees before top dead center ( TDC on the balancer) The timing pointer is on the timing cover, either on the left or right, oposite side from the water pump inlet. The balancer marks are on the thick side of the balancer, you'll probably need to take a wire brush and clean the rust/paint/dirt off the balancer to find them