My 2006 Mariner 75HP is not reaching more than 4,100 RPMs under load. It has the same propeller, and no additional load or modifications have been done to the boat. The temperature and oil level signals are normal and no activation of the alarm is present. (I verified the sensors and are working ok). The spark is good on all three cylinders. Do anybody have any clue on the possible root cause of this problem? The engine can reach speeds higher than 4,100 without load. A compression test shows all cylinders having 135PSI.

probably dirty carbs or a restiction in fuel delivery system. may need to remove and clean carbs and check for bad fuel hose or plugged fuel pickup in gas tank.

__________________
Regards
Boats.net
Mercury Outboard Parts
MerCruiser Parts
Force Outboard Parts
Mariner Outboard Parts