1987 Mercury 45 HP / 4 Cyl.. Rev Limit?

dd716ted

Petty Officer 2nd Class
Joined
Aug 26, 2002
Messages
109
Whenever we take our fishing boat out for the first tiome in several weeks, the Mercury 45HP starts immediately and idels perfect.. Quite as a 2 stroke can be and very smooth.. When we leave the dock and crack the throttle open, the engine accelerates normal and continues to do so until the RPM's reach 3200 and then no matter where the throttle handle is.. won't go any faster...it is still runningvery smooth.. but no faster..
After running this way for about 5 / 10 minutes, suddenly the engine takes off and continues to full throttle (about 5200 RPM's) and for the rest of the day works perfect.. even after using the kicker for several hours, the 45 works as it should throughout the throttle range. This problem seems to happen after a week or so period of engine inactivity.. Then the same thing happens over again.. Something is limiting RP)M's for a period of time to 3200.. any ideas what is causing this?
 
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