New to me 1920's Seascout 109 is overheating. Mechanical water pump works fine. A garden hose connected to isolated areas shows consistant flow to all areas except reduced flow and increased pressure through the manifold. Is this normal or an indication of a restrictred path through the manifold? How should the gate valve that deverts water between block inlet and manifold inlet be adjusted. Any wisdom on solving overheating problem appreciated. Thanks, Dave