I have recently purchased a 1987 weekender 30 with a pair of freshwater cooled 350 cubic inch 260 h.p. engines that have 800 original hours.These engines run very well and have been dealer maintained , the hoses are recent and overall apearance look almost new.The weekender has straight drives and warner transmissions.The fluid has been changed once a season and is the proper red color.<br />When idling at about 600 rpm's in gear the port engine is perfectly quiet, as the rpm's are increased a sort of howling noise starts. This noise becomes louder as the rpm's are increased and at 1000 it is quite loud. If you shift into neutral at any time while the noise is there the noise totaly stops.If you increase the rpm's above 1000 the noise totaly dissapears.The transmission shifts properly foward and reverse seem perfectly normal and the boat cruises at about 25mph doing 3500 rpm's.<br />I have plans to make a trip up the hudson river this season and would like to know if this noise could be something serious or not.<br />Also both engines run about 165 degrees at cruising speed, when I feel the rises they are on the cool side. When I feel the manifolds they are hot enough that you would not want to keep your hand on them to long.The manifolds are fresh water cooled also.Approximately what should the manifold tempertures be.<br />Thanks for any help in these matters<br />handball
