My engine won't cool. I have a 1973 Tom Sawyer Waukesha 302 with a Volvo lower. I changed the impeller on my raw water pump. I used a set of ear muffs. I primed the engine. I also stuck the lower unit in a drum of water. it wont cool. Also is there another name my Waukesha engine goes by? I cant find any info on it what so ever.