Engine noise

I recently acquired a 2002 225VMAX with 120 hrs on it. I have known the previous owner during the entire life of the engine. I know for a fact it has had all required maintenance.

I'm having an issue when I run it above 4200 rpms's. I start to hear a clanging noise in the engine. Most people do not notice it but since it's my engine I know its not the same sound it usually makes. At first I was not too concerned with this but the next time I took it out I noticed it was making the same noise running 3700 rpms trimmed up a little higher.

Does anyone have any thoughts on what this could be?

Thanks!!

[boats.net]

Do a compression test on cylinders. Remove lower unit and check the exhaust tuner.

So I got home last night and took out the spark plugs, all good. Then put the engine cowling back on. Noticed the rear starboard cowling latch was not locking. Took the cowling back off and noticed the cowling latch was a little corroded. Sprayed with corrosion block and greased it up. Then manually worked it (locked and unlocked) a few times. I then put the engine cowling back on and really had to push but I got it to lock. Took it out yesterday in Tampa Bay (2-3 ft) and couldn't hear it. I got a compression checker and will test it out just in case. Hopefully I'm in the clear.

Does anyone know why kind of compression I should be getting on a 2002 Yamaha 225 VMAX (3.1L OX66)?

[boats.net]

The compression should be even, no more than 10% difference between cylinders.

Compression was between 98-106. I think I'm in the clear in that aspect. I'll let you all know if I still hear the noise this weekend. Thanks for the help!