Have Boat Questions? Ask a Boat Repair Expert.
Hello, my name is***** will assist you.
with the sound increasing with the RPM, this could really be anywhere on the engine. Start with a compression test and make sure that all 6 are over 180 PSI and with in 15% of each other. Then test the spark, you could just have a bad coil on the engine.
Change the gear oil, it is not supposed to be like mud. Just 90W oil
Also, would you please post the full model number of the engine?
you are going to need to drop the lower unit and inspect parts 29 and 38. 29 would lead to loud exhaust, and 38 could be the source of the chirping sound.