HELP. Our 1987 sunbird 3.0 181 4 cylinder mercruiser is popping out of the carbuerator then it misses and looses power ( may or may not make it to the dock. The condenser and coil gets hot. But, It only does it when we run it 1/2 hour or approximately 15 miles. <br />It does not have a power pack. <br /><br /> We currently have it at the shop. They have tried new ignintion. Complete tune up. We have changed the entire fuel system with the exception of the fuel tank. The shop has ran it for two days. No ideas except it may be in or on the motor somewhere. <br /><br />Has anyone had this or a similar problem?? Help... No ideas. Shop is baffled. Any help would be appreciated.<br />Thanks