I have a 1997 Wellcraft Martinque with twin Closed Cooled 7.4L Mercruisers with V-Drive and one is overheating when under power. At under 2500 RPM it is fine, but when I try to get on it, it will shoot up to 200 and the other engine runs at a cool 155-160F. If I back off it will cool down. So...
