Starting on Muffs: How do I know?

Subliminal

Chief Petty Officer
Joined
Oct 21, 2009
Messages
555
Hey folks,

So, I'm a new boat owner. I've a VP 4.3GL with the SX-A drive.

Basically, I believe it's good practice to start the engine at home...that way the chances of issue at the ramp are minimalized.

I have a set of muffs, and when I started the engine at home the other day, water didn't seem to come out of the engine anywhere...not sure if it wasn't sucking it up, or what.

Any advice on how to know that everything is good with the muffs? My neighbors outboard shoots water out of a hole in the side of the engine when it's sucking the water properly...not sure where mine is supposed to go.

Thanks!

damon
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Starting on Muffs: How do I know?

i don't know where your water is supposed to exit and you do need to find out where and what normal is. but one thing that i'd think would be common would be. when my muffs are installed and ready to go. i turn on the water. the water comes shooting out the sides and all around the muff edges. after i start my engine. water no longer exits around the perimeter of the muffs. it's getting sucked up and is feeding my engine with water flow. this is one way i know that i'm getting cooling water to the engine. where it exits is the another. mine exits in 4 places. again, i don't know where water exits your vp. bet someone else will know though.. ;)
temp gauge being in the normal operating range is another good sign..
 

RL Gman

Petty Officer 2nd Class
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Apr 16, 2010
Messages
192
Re: Starting on Muffs: How do I know?

The water discharges out of the outdrive next to the transom (on bottom) for my drive (alpha 1). When I run it on muffs it takes a little time before the water starts pushing out though, it's definitely not immediate.

And nothing like the old O/B's, those were always easy to tell if you were getting good water flow! I do miss that with the I/O.
 

ziggy

Admiral
Joined
Jun 30, 2004
Messages
7,473
Re: Starting on Muffs: How do I know?

The water discharges out of the outdrive next to the transom (on bottom) for my drive (alpha 1)
yours should be similar to my 1 drive. water exits in 4 places. prop hub, 2 idle relief ports (port and starboard), pee hole in ft. of the bullet on the lower. the op has a vp so his may be different.
When I run it on muffs it takes a little time before the water starts pushing out though, it's definitely not immediate.
mines pretty immediate. water is exiting all 4 places by the time i get to the rear of my boat from start up. and that's the first thing i do after start up on the muffs is go look to see water exiting. i look at it this way. the block is full, the manifolds are full. only thing that hasn't got water in it is anything from the riser down to the exiting the drive. and our idle relief ports are just down stream from the risers. i feel water should exit almost immediately. if it don't somethings amiss and i start to worry. this excludes when i start with an empty block and manifolds from draining the system for freezing weather. then it takes a moment (30 sec. plus or minus roundabouts) for the block and manifolds to fill, then go up and over the riser and out.

i apologize to op for talking mercurisers on your vp thread. wish i had the facts for ya for yer vp. but i don't... still think the water exiting around the perimeter of the muffs when water is turned on and then no water exiting around the perimeter of the muffs after start up could be relevant though.
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Starting on Muffs: How do I know?

Water exits wherever your exhaust exits.

Don't VPs have a water connection INSIDE the boat because of the engine mounted seawater pump?

We need some volvo people, all us merc guys are just guessing.....
 
Joined
Apr 13, 2010
Messages
22
Re: Starting on Muffs: How do I know?

The water will exit through the exhaust... Just above the prop on your outdrive. I believe the engine thermostat must be open (engine warmed up) before the water will travel up through the exhaust manifolds and exit via the exhaust. Until then, it is returned to the pump and re-circulated, so that may be why you're seeing the delay!

I have a 4.3GL VP, but have yet to run it on muffs, but I'm more than half way thru the manual!
 

RL Gman

Petty Officer 2nd Class
Joined
Apr 16, 2010
Messages
192
Re: Starting on Muffs: How do I know?

yours should be similar to my 1 drive. water exits in 4 places. prop hub, 2 idle relief ports (port and starboard), pee hole in ft. of the bullet on the lower. the op has a vp so his may be different. mines pretty immediate. water is exiting all 4 places by the time i get to the rear of my boat from start up. and that's the first thing i do after start up on the muffs is go look to see water exiting. i look at it this way. the block is full, the manifolds are full. only thing that hasn't got water in it is anything from the riser down to the exiting the drive. and our idle relief ports are just down stream from the risers. i feel water should exit almost immediately. if it don't somethings amiss and i start to worry. this excludes when i start with an empty block and manifolds from draining the system for freezing weather. then it takes a moment (30 sec. plus or minus roundabouts) for the block and manifolds to fill, then go up and over the riser and out.

i apologize to op for talking mercurisers on your vp thread. wish i had the facts for ya for yer vp. but i don't... still think the water exiting around the perimeter of the muffs when water is turned on and then no water exiting around the perimeter of the muffs after start up could be relevant though.

You are absolutely right, but when on muffs on the trailer, (and I should have said originally) most of the water comes out by the transom. As for if it is immediate or not...

Right after it starts up, I walk back, jump off the boat and wait for the water. Now, when it hasnt been drained, sure I see water spitting out of the exaust ports, but definitely not much. I count to ten in my head, and by about 7 or 8 the water is definitely pooring out of the transom (so not immediate for me, but definitely quickly). Perhaps I should have been more clear, hopefully this makes more sense Ziggy? (seriously courious, because I dont think I have any issues with my cooling system, and I had actually just changed everything out and put her in for a test drive!)

I too must apologize to the OP with all of this Merc talk, but I guess I kind of assumed it would be similar, obviously not the same. The water HAS to come out if it is raw water cooled and water is being supplied. And Like Bubba said, it should be pumping through the exhaust manifolds very quickly!
 

Subliminal

Chief Petty Officer
Joined
Oct 21, 2009
Messages
555
Re: Starting on Muffs: How do I know?

Lots of information, but no easily discernable answer. When I hooked up the muffs water was shooting out of the side of the muffs. I started the engine, and there was no visible change. I swapped the muffs to the other side and no difference. I tried to squeeze them so water couldn't shoot out the side to no avail.

I just don't want to burn my stuff up from starting it out of the water.
 
Joined
Apr 13, 2010
Messages
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Re: Starting on Muffs: How do I know?

Umm no, it should start pumping through the exhaust manifolds immediately. Other wise you'll burn up the bellows. As a general rule (unless you have exceptional water flow) when running on muffs the water will run out at the transom, especially if the outdrive is up.

Ok, I stand corrected... That makes sense and I apologize for the incorrect info! There's a bypass in the thermostat housing that let's the water flow out beyond as it were! Reading and comprehending are 2 different things I guess! :)
 

wperson

Cadet
Joined
May 27, 2009
Messages
15
Re: Starting on Muffs: How do I know?

The problem you had when you squeezed them is that i believe you have a
impeller pump that isn't taking your water. Those pumps are very good at sucking and disposing liquids. But the usually don't produce that high pressure, so if there is any restriction on the in/outlet side of the pump you would have poor performance. Disconnect hose on outlet of pump and see if
the pump works when starting the engine for short period of time. If that is working try losen hoses further down the line to determin whats wrong (heatexchanger, exhaustmanifold).
 

Subliminal

Chief Petty Officer
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Oct 21, 2009
Messages
555
Re: Starting on Muffs: How do I know?

The problem you had when you squeezed them is that i believe you have a
impeller pump that isn't taking your water. Those pumps are very good at sucking and disposing liquids. But the usually don't produce that high pressure, so if there is any restriction on the in/outlet side of the pump you would have poor performance. Disconnect hose on outlet of pump and see if
the pump works when starting the engine for short period of time. If that is working try losen hoses further down the line to determin whats wrong (heatexchanger, exhaustmanifold).

The boat has approx. 3 hrs on it now. The pump should work fine, being that it's brand new.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
Messages
28,771
Re: Starting on Muffs: How do I know?

Your boat also has a water temperature gauge. I suggest you look at it. It will tell you in a hurry whether the engine is getting water or not (closed or raw water system). And while you are looking at it, cast a glance at the voltmeter as well. It will tell you if the charging system is working. And of course oil pressure is in that mix somewhere too. The gauges are there for a reason but do not good unless they are monitored. And if you monitor them, understand what they are telling you.
 

jmr12

Cadet
Joined
Apr 12, 2010
Messages
13
Re: Starting on Muffs: How do I know?

Sub
I have a 03 VolPen 5.0 I bought it in March. I changed the sea water pump. Hooked up the muffs and started it. No water comming out. Removed the sea water pump again and made sure every thing was hooked up correctly. I have a Engine Flush hose on the boat. I ended up putting the muffs on but put a plug in where the garden hose hooks up, and supplied water to the engine flush. Started the boat, wacked the throtel a couple of times, about 2000 rpm, and within a few seconds had water comming out where it is suppose too. I called the guy that winterized the boat for me and he said that it takes awhile for water to get to where it is suppose to. I think the next time that I start the boat in the spring I will see how to fill the exhaust mannifolds before I start it. On my engine there is a plug on top of the manifold. I think that I will try to pour water in that to fill them. Also, I think that when I started the boat the first time, with the muffs only, there was enough water to cool the block but not the exhaust Mannifolds. The water temp gauge never went over 120 deg but the mannifolds were hot to the touch. After the system filled with water, I could hold my hand on the mannifolds.
 

milmat1

Petty Officer 2nd Class
Joined
Apr 29, 2010
Messages
137
Re: Starting on Muffs: How do I know?

Umm no, it should start pumping through the exhaust manifolds immediately. Other wise you'll burn up the bellows. As a general rule (unless you have exceptional water flow) when running on muffs the water will run out at the transom, especially if the outdrive is up.

What is a Bellows ??
 

Subliminal

Chief Petty Officer
Joined
Oct 21, 2009
Messages
555
Re: Starting on Muffs: How do I know?

Your boat also has a water temperature gauge. I suggest you look at it. It will tell you in a hurry whether the engine is getting water or not (closed or raw water system). And while you are looking at it, cast a glance at the voltmeter as well. It will tell you if the charging system is working. And of course oil pressure is in that mix somewhere too. The gauges are there for a reason but do not good unless they are monitored. And if you monitor them, understand what they are telling you.

Oh, I'm aware that my boat has gauges. They're pretty and glow red when the lights are on too.

However, being that I run the thing for just a minute or less, I'm not so much worried about the engine overheating as I am about the impeller getting toasted from spinning with no water flowing through.

Maybe I'm worrying about nothing...I've certainly never revved it while on the muffs.
 

Subliminal

Chief Petty Officer
Joined
Oct 21, 2009
Messages
555
Re: Starting on Muffs: How do I know?

Sub
I have a 03 VolPen 5.0 I bought it in March. I changed the sea water pump. Hooked up the muffs and started it. No water comming out. Removed the sea water pump again and made sure every thing was hooked up correctly. I have a Engine Flush hose on the boat. I ended up putting the muffs on but put a plug in where the garden hose hooks up, and supplied water to the engine flush. Started the boat, wacked the throtel a couple of times, about 2000 rpm, and within a few seconds had water comming out where it is suppose too. I called the guy that winterized the boat for me and he said that it takes awhile for water to get to where it is suppose to. I think the next time that I start the boat in the spring I will see how to fill the exhaust mannifolds before I start it. On my engine there is a plug on top of the manifold. I think that I will try to pour water in that to fill them. Also, I think that when I started the boat the first time, with the muffs only, there was enough water to cool the block but not the exhaust Mannifolds. The water temp gauge never went over 120 deg but the mannifolds were hot to the touch. After the system filled with water, I could hold my hand on the mannifolds.

Hey thanks for that. :)
 

wperson

Cadet
Joined
May 27, 2009
Messages
15
Re: Starting on Muffs: How do I know?

Do you have a closed cooling system on the engine?
As long as you have water as a lubricant to the impeller there is no problem,
but if there is no new water getting through it will sometime get hot and maybe get damaged. I have been running my engines ( with closed system) and without impellerpump engaged for severel minutes without over heating
exhaust hoses and bellows.
 

z284u2try

Petty Officer 3rd Class
Joined
Dec 11, 2006
Messages
91
Re: Starting on Muffs: How do I know?

Look under your boat in the rear area and see if there is another water pick up. I know on some boats they have another water pick up.
 

RL Gman

Petty Officer 2nd Class
Joined
Apr 16, 2010
Messages
192
Re: Starting on Muffs: How do I know?

Look under your boat in the rear area and see if there is another water pick up. I know on some boats they have another water pick up.

Even with VP outdrives? I thought both merc and vp only had pickups on the outdrive itself?
 

skargo

Banned
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Sep 14, 2008
Messages
4,640
Re: Starting on Muffs: How do I know?

Even with VP outdrives? I thought both merc and vp only had pickups on the outdrive itself?

My Alpha one gen one has a thru-hull pickup, and an engine mounted seawater pump, no pump in my drive so that is not an all encompassing statement ;)
 
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