My starboard engine just developed a definitive rap this past week. It has run fine all year. Its a 2001 OX66 200HP Yamaha. No noise in neutral. Only heard under load. Gets louder as load increases. Will be taking boat to mechanic unless I can figure what it is. Pulled Spark Plugs, and they seem fine. All plugs appear the same. Checked for movement in pistons at TDC and everything seems solid. Checked, drained, and refilled LU. Some metallic fines but not excessive? Engine seems to have plenty of power, just with a rap. This engine does smoke more than the port engine, but from what I read about these 2 stroke engines, my oil usage is not excessive. I run Ring Free pretty regularly. I have had the boat for 4 years.
What should I check before breaking down and delivering to Yamy Mechanic.?
Thanks in advance.
What should I check before breaking down and delivering to Yamy Mechanic.?
Thanks in advance.