Need muffler/ fumes advices

[Hudsteve]

We took the muffler off to hoist the engine and change the transmission

Now everything is put back together and I have (what I think) is excessive fumes and noise coming from the port engine.

I open the hatch and everything is perfect, no fumes, smoke or anything out of order

Everything comes out of the back exhaust just above water level

Note the Starboard side is much quieter and no fumes at all

I have no idea of what it should be like as I just bought the boat and can only compare it to the starboard engine

They are crusader 454's

Any advice, knowledge would be appreciated

Should the muffler have water in it?
If so, Was I suppose to put some in before I connected everything back up?
Is there a baffle inside that could be bad?

Thanks
Steve

[Viper]

Most marine mufflers retain water, that's how most designs muffle the sound. You don't have to fill with water first as the raw water running through your engine will eventually fill the muffler as long as your raw water pump is working, so you need to confirm that water is actually coming out with the exhaust (if no separator). We really need to know the type of muffler you have as that makes a difference. If it's a lift muffler that sit's on its base on a platform, there's really no wrong way to remount it except to ensure you've connected the exhaust hose from the engine to the input port of the muffler. If it's an in-line muffler, depending on the design, it could be mounted wrong as the is a "TOP" side to it that must be facing up for it to work correctly. Both designs have internal baffles. Typically, if a baffle has let go, you'll hear it banging around inside the muffler while the engine is running.

When you say fumes, do you mean exhaust smoke? Some is normal and really should have nothing to do with the muffler. Unless you have an exhaust/water separator which separates the water from the exhaust and directs one below the waterline and the other above the waterline, all water and smoke should exit the same port. The colour and smell of the exhaust and how much is what can tell you about what's going on with the engine. If it's just white smoke, it could be steam which indicates a cooling water flow issue. If it's blue smoke, it's burning oil, excessive black smoke, burning rich, etc. A sheen on the water or could be raw fuel from a cylinder that's not firing or running too rich. You'd also notice a difference in the water. In short, we need more specifics about what you mean when you say "fumes."

[bud37]

Yes....verify you have water flow out the exhaust. It almost sounds like you are low on flow.......if you don't see water investigate/check the impeller and don't run the engine as you will damage/burn the rubber exhaust hoses.

If that turns out to be the case and you have run the engine dry for any length of time you will have to have your exhaust hoses inspected closely.....good luck and lets hope it is not that.

[Hudsteve]

Thanks for the replies

I will go take pics in the next day or two, but I believe it would be a lift muffler as there was only
one way to re install it.

I changed the impellors 1st thing this year and I do have water exiting the exhaust.

By fumes smell, I mean fumes that kinda make you sick when you breathe to much, like exhaust fumes from the back of a car, I do have a little white smoke that I was told was normal due to cold water temps in Lake Michigan (No black smoke)

If you ride in the back of the boat 32 carver montego it will get to you a little bit while going wake speed until you get out on the lake where the wind will finally take it away

I ran it up to 20mph 2 days ago and the water temp stayed right at 140, same for both engines, so I think the impellors are working ok

But while warming it up at the dock I just have way to many fumes compared to basically nothing from the starboard side

thanks and I will try whatever ideas you have for me

[Cooler]

You may have a problem with a connection point in the exhaust hose. Check to make sure all joints are connected and overlapped. The end of a hose, or connector, may have cracked when being pulled off to remove the engine. Or, the straps holding up the actual mufflers could be off a bit, creating a separation at a joint. You are required to have 2 clamps at each connection point also. The exhaust hose is a real bear to disconnect, so they can get torn at the very end easily. er

[chpsk8]

Also sounds like it's running rich. Is this carb'd or fuel injected?
Are you smelling the exhaust inside? Or just outside?
Are you running with canvas up?
You can and will get a station wagon effect with exhaust if you don't have ventilation.

[Hudsteve]

Cooler

Yes your are correct they are a "Bear" to take off and put together

they have 2 clamps each and we didnt see any cracks in the fiberglass elbows or the muffler itself

You mentioned "Straps" to hold it up...I do not have any straps as it will not hardly move when it is together,,,everything is very snug fitting together

Is it possible that I dont have it perfectly level or is there something like that, that will make the difference...It really only goes together one way

I am just comparing it to the starboard motor that is much quieter and no fume smell at all

Btw Is there anything inside the muffler? carbon filter or any kind of baffle? Maybe it came out and I didn't notice to put it back in? But I do not remember having any parts leftover at all.

Thanks

Chpsk8

I just rebuilt the Rochester 4 barrel carb, it sounds good but very well could be off a little

I can change anything out if you tell me what is wrong...but not good at all in diagnostics department

I took off 80% of the canvas and will take off more on the next trip, but I only have it at the slip when warming up the engines or at wake speed going out to the lake

Only have the smell outside, nothing at all in the engine compartment when I open the hatch

thanks
Steve

[Viper]

I agree with Chpsk8, you may just be smelling the results of an engine that needs to be tuned properly. You can't get away from an exhaust smell, that's just the way it is with all internal combustion engines but a properly tuned engine and good fuel will help minimize the results of an improper burn to a degree. That has nothing to do with the muffler, it's simply releasing what went into it to begin with, and there are no filters inside it. As mentioned above, if it's a lift muffler that sits on it's base on a platform and you put it in the same spot, it should be fine.

If you're determining that one side is noisier than the other in the slip where you're docked, I suggest you take her out in the open and have a listen again. Surrounding structures at the dock can affect the harmonics and make it seem like one side is louder than the other. Even standing in different areas of the boat will do that.

[Hudsteve]

Thanks
Do you know of a good video to tune the Rochester 4 barrel carb?
I do appreciate everyone who gave advice
Steve

[bud37]

Steve....the tuneup is probably in order, good to hear there is water flowing properly...that is one hurdle.

Now if you are smelling fumes that may be a good thing because it is making you aware of the station wagon effect at the back of boats. The canvas layout of the Montego ( or any boat for that matter ) contributes to this. Now along with that you were saying it made you feel sick or off...don't just assume that is just the raw gas fumes, that could quite possibly be Carbon Monoxide ( CO )...very dangerous....so try to have canvas open at the front to create a thru flow out the back to break the suction effect. There are quite a few articles about this if you google it.

You could put a monitor near the helm where you are breathing to keep a check on this, don't let people in the cabin while underway unless you have up to date working CO monitors in the cabin area....be careful.