2001 mercury/tracker Outboard won’t rev above 3k Rpm

[Swampthing83]

Took my boat out for a quick trip this morning it ran fine. On my way in at 28mph and a little over 5k rpms it suddenly acted as if it was running out of gas. I shifted to neutral killed the motor and went to swap tanks but the tank had plenty of fuel. I started the motor with no problem but it will not accelerate above 7mph and about 3k rpms. It will rev slightly higher in neutral but still only getting up to about 4K rpms. The boat is a bass tracker pro17 and the motor is a 40hp 2stroke. Any ideas on where to start will be appreciated. Thanks in advance.

 

[racerone]

Have you maintained the water pump ?----Check compression and do a spark check.-----Sounds like it is not running on all cylinders.