Port exhaust Louder than Starboard

[bulletine]

On my 89' 454's the starboard engine exhaust is very quiet. The port side is much louder and the water has more a spray to it than the other side. I am sure this is not my imagination ) The reason I started observing this was my generator trips a circuit breaker which I believe is due to a high exhaust temperature.

Both the 454's always run at 160 and there are no known problems with the engines, this week )

My question then is about the muffler, is this something that needs replacing, cleaning, or what?

Thanks

 

[fastjeff]

Possibly. Water makes them quieter--I can hear the motor go quieter as the water starts to flow at start up. If your motor is pumping enough water through itself then it has to be the muffler internals are shot.

Jeff

 

[bulletine]

I have mnore information as I was just out on the boat and checked the exhaust set up. Both engines have the same set up, 4" running from the manifolds to a muffler which appears to be FRP, DIFFICULT TO SEE IN THERE. From these mufflers they run to the outlet through the hull. Right about the water line is where the exhaust fumes exit. I see no problems here.

What I do have that puzzles me is a separate exhaust system running from the generator's exhaust manifold via 2.5 or 3" hose to a round canister. Then another hose the same size exits the canister and to a thru hull fitting next to the part engine exhaust. Where I am having my problem is the generator shuts down and I was assuming it is because of the temp in the exhaust. Since I can get it to run for any length of time (5 minutes at most, but more like 1 minute) I have not been able to check the system while running. It very well could be this canister, but I need to see how the raw water is flowing through the exhaust before I condemn a part.

I would prefer to isolate this problem and repair it, but it may be beyond my limited skills (parts re placer). I do not want to start throwing parts at it because Onan parts are out-of-this-world for pricing. It may be cheaper in the long run to call in a spe******t ($100 per hr, ouch).

Not being too stubborn, I will think this through and perhaps find the problem.

Thanks Fastjeff.

 

[RMS]

I'm confused. Is the problem you are trying to solve a) the port engine running louder than the starboard engine, or b) that the genny does not stay running? The problems should not be related. The canister is the generator muffler, which sounds like the setup I have. How is the water flow from the generator for the short time the genny runs? Do you have an IR temp gun to check the genny temps? Will the genny stay running if you keep your finger on the primer button (which typically defeats the hi temp/low oil pressure shut off's)? Bob

 

[willow]

I think you are atributing the genny shutdown to the fact that your port engine is running a bit louder than normal and you may feel that the port engine exhaust discharge, or lack off, may be what is effecting the genny.

As you have stated, the genny has a seperate exhaust system, and rightly so, as I have never seen a genny exhaust hooked up with and engine exhaust.

1. The fact that the port engine runs louder will have absolutely nothing to do with the genny, the genny is a separate machine with its own ehaust system, the cannister, is your muffler.

2. The port engine may be running a bit louder due to lack of sufficient water running through the cooling system, (impeller problem/plugged, corroded exhaust system) or it may just be running a bit louder with no real cooling problems

3. The genny could be shutting down because of a) overheat...check the impeller and ensure sea cock is open and water filter is clear, b) lack of oil pressure...check the oil quantity, c) lack of sufficient fuel pressure...check the fuel filter probably located near carb.....I have an inline filter as well.

My genny is a Westerbeke and once I forgot to open the sea cock and it shut down from overheat...and it really got hot....was easy to find that problem

Time to purchase an IR heat tester...not expensive...

Good luck:rolleyes:

 

[makomark]

There is a lot of confusion in the original post. suggest a repost of the most pressing issue here and start another thread of two for your other issues....regarding the noise differences between engines, based on the description, I'd suspect the loud side has suffered an overheat in the past and the muffler likely suffered as a result. Replacement is the most likely path. As Jeff noted, a lot of the 'silencing' effect is due to the raw water being dumped into the exhaust.

 

[bulletine]

Thanks, I will try to explain better.

1) The prot engine is louder than the other, but this is not a problem. At first, I thought the port engine and genny were tied into the same exhaust, but after checking this morning, they each have their own exhaust. I believe the port engine is louder because the genny is on the port side of the boat and the exhaust port for the Port engine in a little deeper in the water than the other side. This is the only thing I can think of, and the Port engine runs fine.

2) The Onan runs for a minute or two and shuts down as the circuit breaker is tripped. As far as I have been able to determine, the temp in the exhaust is tripping the circuit breaker because it (exhaust hose) really gets hot and I suspect not enough water is flowing through the exhaust to cool. I have not used the IR gun, I will tomorrow. I do know the genny is much louder than it used to be when I did have it running. This is one reason I am focused on this. The three other possible cause for the circuit breaker to trip is low oil pressure or high engine temp. Both of these are fine.

I waited 2 months to get all the parts for the new raw water pump and I installed it this week. I flushed the raw water system looking for restrictions and did find some impeller pieces in one of the hoses. I also flushed the heat exchanger. My next step is to check the flow in the exhaust manifold, I checked every thing else as far as I know and everything seems to point to the exhaust manifold (in my limited ability). It could also be a problem with either the circuit breaker or control board. But....What has me convinced is the exhaust because it is very loud now, it used to run quietly.

The fresh water cooling system uses a electric pump to push water through, I replaced this cooling pump last year. The engine is not to hot. The block is fine and the 2 thermostats open at the right temp, well they did last year when I tested them. New spark plugs last year.

The fuel is good (new) and I rebuilt the carb 2 years ago. But it does need a little adjustment to the choke. But this should not cause it to cut out.

The generator is a 1989, and only has 123 hours. So it is in good condition. I can say this generator gives me more problems than my 2 ex-wives.

Thanks Guys, your help is always my best source for help.