Mercruiser 4.3L

[Jeff62]

Placed boat in water for the season two weeks ago. All fluids, filters changed during winterization in the fall. Took the boat out for two runs the first day. The second day upon starting the exhaust sounded muffled. (glasspacks) All of the norm opertaing temps and pressures are normal. No loss of power and engine runs smoothly and no strange noises.

Any suggestions.

Thank you.

Jeff

 

[Bondo]

Re: Mercruiser 4.3L

Ayuh,...... What's the Problem,..??

Are you saying the Exhaust is too Loud,..?? Look for a Leak......

 

[BAYLINER185]

Re: Mercruiser 4.3L

Well My 4.3 sounds like a 454 when out of the water on muffs.

My 454 sounds like my friends 496(in the water) when its out of the water.

Both motors sound quiet and ballsie when thier in the water.

Maby you just arent used to the sounds of the motor? Could it be all in your head since the motor is running fine with all new fluids and such?

 

[marco_0521]

Re: Mercruiser 4.3L

Jeff,

A friend of mine replaced his exhaust bellows with a tube and for sure it sounds much louder now. In the case of a tube, only one end is attached to the transom. Can you check that both ends of the exhaust bellows are perfectly attached?

Some people dont glue them and if they are not tight they might come off. If they came off, there is no really any deterioration in performance or malfunctioning unless they obstruct something, but the sound surely is different (generally louder than before).

Good luck,

 

[BAYLINER185]

Re: Mercruiser 4.3L

Good Point Marco I didnt think of that. I pulled my Bellows on my boat 10 years ago because I thought it would run better. It didnt lol. A 3.0 is still a 3.0 That didnt do anything for power but it made it sound louder and bubbled a lot of water so I put the bellows back on.

 

[Jeff62]

Re: Mercruiser 4.3L

This past weekend checked everything I could think of. Replaced the plugs and searched for exhaust leaks. NOTHING. The "muffled" noise remains, no loss of power and all gauges remain OK and stable.

I need assistance in finding the noise problem. Has anyone ever this problem?

Help, please.

Jeff

 

[JustJason]

Re: Mercruiser 4.3L

maybe ya lost your flapper and its stuck in the tube....

 

[Jeff62]

Re: Mercruiser 4.3L

Thank you Captjason - Now be patient I am a new I/O owner. Had outboards for many years. Is the flapper the thin layer just in front of the transom? Where the exhaust is emmitted along with the water from the engine?

Thanks. Jeff

 

[bjcsc]

Re: Mercruiser 4.3L

Thank you Captjason - Now be patient I am a new I/O owner. Had outboards for many years. Is the flapper the thin layer just in front of the transom? Where the exhaust is emmitted along with the water from the engine?

Thanks. Jeff

No, not that one. The internal one. The real name for it is water shutter. Since we don't know what 4.3 you have, here's a general pic (#7)

Go here, pick your engine and then lookup "water shutter". It will show you where yours is...

 

[Jeff62]

Re: Mercruiser 4.3L

OK, so now I will zero in on this part. I have never never worked on an I/O other than replacing plugs, and winterizing. How indepth is the replacement of the water shutter. It looks fairly easy. What tips are out there?

Thank you for all of your assistance.

Jeff