Yesterday I ran through a kelp bed and within a few seconds my alarm came on so I shut down the engine. I assumed that the water intake had become clogged and caused a temperature rise although I did not see any smoke around the engine. I didn't check the temperature of the motor housing but nothing seemed abnormal. I did kick it into reverse before I shut it down in order to see if I could get rid of the kelp. Since I was close to where I wanted to fish I turned on the kicker and fished for a few hours and then restarted the main engine. It started easily. HOwever when I was running back to the dock it would not run up to full power. It would only run up to 3700 rpm and was slow to get up on plane. It did not seem to be misfiring but it did not seem to be running freely either. Any ideas?