[aman69]

Hi to All,
I have purchased 2007, Yamaha F20ESH a month ago. It is 20hp, 4 stroke, short shaft, electric starter. S# 6AHKS100…... I also purchased a tachometer/hour combo meter p/n-ENG-METER-4C-02.

After braking in (1hr. at 2000RPM and 3.5hr. at 3000RPM), I have increased speed to around 5500 RPM and got knocking coming from upper part of motor, apparently close to rear-left. It sounds like- DING, DING….two three times p/second, non-stopping. If speed is increased the DINGING frequency also increases. If speed is reduced below 5500 DINGING disappears. There is no DINGING in neutral at any RPM, and motor runs very quiet below 5500 RPM.

Yamaha Customer Service told me that it is abnormal, and no any kind of knocking or noisy different from working engine sound should be heard. Overrev protection does not create any sound, and F20ESH engine has no alarm. They advised to see Yamaha dealer.

I was running the boat with dealer’s mechanic, today. He confirmed the DINGING but didn’t know what it is. He checked spark plugs (normal), and told me to run motor for remaining 6 hours out of 10 braking in hours. He almost told me that if something brake than he would know what it is. If dinging continue he will run test with test prop. Well,.. I was not happy with that conclusion.

Does any one have the same engine and what is your experience at 5500 rpm? Any similar DINGING? It is my first boat, and first outboard. What should I do? Thank you for advice in advance.

[aman69]

This is additional information to my original question.
It might sound fanny but after 5.5 hours of braking in the type of noisy has changed. It is clear knocking/tapping now, instead of dinging before. The knocking starts at around 5000 rpm, with frequency about once per second, and increases with rpm up to full throttle. At full throttle it sounds like a military drum. No knocking in neutral up to full throttle. Dealer advised to run motor to the end of braking in period, 10 hours, and than call him back. Thanks for advice in advance.