I have twin 87 135HP merc black max outboards. The starboard engine runs fine with no load. In the water full power is 2k RPMs. I can use the other engine to provide enough power to start the plane which the starboard engine increases RPMs which allows the boat to plane and can run 4k RPMs and if increase the power to the good engine the starboard engine increases also. I had two mariners try to fix it. First one replaced both ignition swich boxes, no help. The other stated he replaced the stator and used the dyno which results show 135HP. Compression is good and good spark to all 6 cylinders. Not sure what is going on. Any ideas would be appreciated and am I doing harm to the engines if I continue to run with the engines as is. 1987 GW (GS) boat if it matters. <br /><br />Note: Not sure if this means anything. I noticed that my batteries appear low of charge which could be because eng not running and bring them up and down constantly. <br /><br />Thanks for listening...<br /><br />ALH
