Mercruiser over heating!! Help

[ademelo]

Last weekend I purchased a 1987 Four Winns/Cuddy with only 30 hours on the motor, and the seller explained that we shouldn’t go over 30 mph until the motor gets at least 50 hours on it. It made sense so we took it for a test drive and it ran great.<br />This weekend when I took it out it wouldn’t go over 10 mph, AND it was overheating!!! We stopped to cool it down and then my boyfriend checked the anti-freeze and saw that it was leaking out. We managed to get some more in but we had to keep stopping because of the overheating. Does anyone know what happened and how this can be fixed? And why is my speed so low? <br />Please help.<br /><br />The motor is I/0 180 Mercruiser, 221 CID, fresh water coolant. <br />Thanks,<br />Ana

 

[magster65]

Re: Mercruiser over heating!! Help

We need more info. It's very difficult to diagnose things without looking at them.<br />Does the motor rev up?<br />Does it bog?<br />Is the throttle moving?<br />Does it heat up right away?<br />Is there any vibration?<br />Anything else relevant?