Idle relief mufflers and outboard motors having idle relief mufflers

An outboard motor, comprising:

• an internal combustion engine;
• an idle relief muffler configured to discharge exhaust gases from the internal combustion engine to atmosphere surrounding the outboard motor when the outboard motor is operated at idle and at low speeds;
• wherein the idle relief muffler comprises an idle relief muffler housing having an open interior, an inlet port configured to convey the exhaust gases to the open interior, and an outlet port configured to discharge the exhaust gases from the open interior;
• and
• wherein the idle relief muffler comprises an exhaust grommet connected to the outlet port, wherein the exhaust grommet comprises a body and an extension that extends through the outlet port and protrudes into the open interior, wherein the extension and the body together define a through-bore that is configured to convey the exhaust gases from the open interior to the atmosphere.

A method of making an idle relief muffler configured to discharge exhaust gases from the internal combustion engine to atmosphere surrounding the outboard motor when the outboard motor is operated at idle and at low speeds, the method comprising:

• forming an idle relief muffler housing having an open interior, an inlet port configured to convey the exhaust gases to the open interior, and an outlet port configured to discharge the exhaust gases from the open interior,
• forming an exhaust grommet that is configured to connect to the outlet port, wherein the exhaust grommet comprises a body and an extension that extends through the outlet port and protrudes into the open interior, wherein the extension and the body together define a through-bore that is configured to convey the exhaust gases from the open interior to the atmosphere;
• and
• selecting an axial length of the extension relative to the outlet port to achieve a certain exhaust noise when the internal combustion is operated in idle gear.