Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 22-01-2019, 03:15   #1
Registered User
 
MollyJo's Avatar

Join Date: Jun 2013
Location: Western Australia
Boat: Viking 30
Posts: 53
Mercury 5hp no water flow

So, my tender motor stopped pumping water. No problem I thought. Fitted a new impeller. The old one looked ok but had one fin facing the wrong way. Not enough to be the problem I thought. Turns out I was right. Now with the new impeller I still have no water flow??
Figured I'd ask before pulling the bottom out again.
Any suggestions? A blockage? But where to look?
__________________

MollyJo is offline   Reply With Quote
Old 22-01-2019, 04:20   #2
Registered User
 
thomm225's Avatar

Join Date: Aug 2011
Location: Hampton Roads
Boat: 1974 Bristol 27
Posts: 4,813
Re: Mercury 5hp no water flow

Is the motor overheating? Did the oil light come on?

When my 2011 Mercury 5 hp 4 stroke stops pumping water the oil light will come on after it overheats.

If it's just your telltale that's blocked, that's different.

Once on my engine, the screen above the prop was blocked. That's the intake on a 2011.
__________________

thomm225 is offline   Reply With Quote
Old 22-01-2019, 05:38   #3
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 6,753
Re: Mercury 5hp no water flow

Poke a wire into the pee hole.
Sailmonkey is online now   Reply With Quote
Old 22-01-2019, 06:38   #4
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,887
Mercury 5hp no water flow

First try the witness hole, disconnect it if you have to and blow it out or see if water flows from the fitting.
Keep your old impeller as a spare, a turned backward blade is common, itís often the motor turning backwards slightly after shutdown.

If you use a wire, use a thin one and fold it over so that your not pushing a sharp cut off end into the hose, cause it may stick at the first turn, wonít hurt anything, but you canít get the wire in.

A thick piece of monofilament fishing line works too if you have any, also good for cleaning out carburetor jets as the monofilament wonít hurt anything.
a64pilot is offline   Reply With Quote
Old 22-01-2019, 09:00   #5
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 3,625
Re: Mercury 5hp no water flow

We recently had a problem with our outboard; discovered all the cooling passages around the cylinder walls were all salt-encrusted... so even though the water pump was working fine (new impeller and all that) and the witness stream looked good...

No water was actually flowing into the cooling jacket... Had to dismantle and actually dig the salt residue out mechanically.

I learned something about our flushing regime, from that. <sigh>

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 22-01-2019, 09:51   #6
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,887
Mercury 5hp no water flow

Quote:
Originally Posted by ranger42c View Post
We recently had a problem with our outboard; discovered all the cooling passages around the cylinder walls were all salt-encrusted... so even though the water pump was working fine (new impeller and all that) and the witness stream looked good...

No water was actually flowing into the cooling jacket... Had to dismantle and actually dig the salt residue out mechanically.

I learned something about our flushing regime, from that.

-Chris


What motor?
Iíve heard a similar story about one of the new Suzukiís and wondered if it was a one off failure or a trend.
What made you determine you had an overheat? What make you dig deeper?

I almost never flush mine, and think that very common with cruisers, Iíve never seen one flushing a motor.
Fresh water usually isnít that available.
a64pilot is offline   Reply With Quote
Old 22-01-2019, 10:30   #7
Registered User
 
Bill O's Avatar

Join Date: Jul 2015
Boat: Bruce Bingham Christina 49
Posts: 428
Re: Mercury 5hp no water flow

Quote:
Originally Posted by a64pilot View Post
What motor?
I’ve heard a similar story about one of the new Suzuki’s and wondered if it was a one off failure or a trend.
What made you determine you had an overheat? What make you dig deeper?

I almost never flush mine, and think that very common with cruisers, I’ve never seen one flushing a motor.
Fresh water usually isn’t that available.
I doubt this an engine specific issue. The "salt" accumulation (most likely calcium carbonate) can occur as it drops out of sea water ~>165F. It commonly happens in inboard engines and generators also.

The other possible salt is aluminum oxide from the OB block itself interacting w/the seawater. Excess corrosion will happen when the seawater is left in the OB and not flushed. Its only a matter of time.

Using a safe engine flush to remove the calcium carbonate build up is probably safe to use in OBs. May need to wait longer or use a stronger acid if the salt is aluminum oxide (check w/the manufacturer to see if its safe to use a engine flush or stronger acid in your OB). As suggested before another way to get the salt out is to do it mechanically (ream out the coolant ports) after dismantling the OB.


Bill O.
__________________
Bill O.
KB3YMH
http://phoenixketch.blogspot.com/
Bill O is online now   Reply With Quote
Old 22-01-2019, 10:34   #8
Registered User

Join Date: Dec 2016
Location: Newport, RI
Boat: Lagoon 41 S2
Posts: 30
Re: Mercury 5hp no water flow

A bad head gasket can cause the cooling circuit to be come pressurized stoping the water from flowing through.
An overheated engine is a common cause of a failed head gasket.
Library70 is offline   Reply With Quote
Old 22-01-2019, 10:44   #9
Registered User

Join Date: Aug 2016
Location: Long Island, NY
Boat: Cal 33-2
Posts: 114
Re: Mercury 5hp no water flow

I had the same problem with my 2-stoke Yamaha 2hp. Had to take the head off and clear the cooling passages mechanically.
__________________
S/V First Tracks
1985 Cal 33-2
JimsCAL is offline   Reply With Quote
Old 22-01-2019, 11:38   #10
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,887
Re: Mercury 5hp no water flow

Quote:
Originally Posted by Bill O View Post
I doubt this an engine specific issue. The "salt" accumulation (most likely calcium carbonate) can occur as it drops out of sea water ~>165F. It commonly happens in inboard engines and generators also.

The other possible salt is aluminum oxide from the OB block itself interacting w/the seawater. Excess corrosion will happen when the seawater is left in the OB and not flushed. Its only a matter of time.

Using a safe engine flush to remove the calcium carbonate build up is probably safe to use in OBs. May need to wait longer or use a stronger acid if the salt is aluminum oxide (check w/the manufacturer to see if its safe to use a engine flush or stronger acid in your OB). As suggested before another way to get the salt out is to do it mechanically (ream out the coolant ports) after dismantling the OB.


Bill O.


Understood, but a motorís coolant passages should never reach 165F or really even close on a salt water cooled motor.
However if there was a design flaw, it could, which would lead to the build up, that is why I was wondering what motor.
a64pilot is offline   Reply With Quote
Old 22-01-2019, 12:14   #11
Registered User

Join Date: Jan 2012
Location: New York
Boat: FP, Eleuthera 60
Posts: 318
Images: 4
Re: Mercury 5hp no water flow

happens often, spiders crawl into the pee hole, use a wire to unclog it
MIRELOS is offline   Reply With Quote
Old 22-01-2019, 12:23   #12
Registered User
 
ranger42c's Avatar

Join Date: Aug 2012
Location: Maryland, USA
Boat: 42' Sportfish
Posts: 3,625
Re: Mercury 5hp no water flow

Quote:
Originally Posted by a64pilot View Post
What motor?
I’ve heard a similar story about one of the new Suzuki’s and wondered if it was a one off failure or a trend.
What made you determine you had an overheat? What make you dig deeper?

I almost never flush mine, and think that very common with cruisers, I’ve never seen one flushing a motor.
Fresh water usually isn’t that available.

Suzuki DF15A, same as yours except horsepower I guess.

The red light came on and it went into limp mode, even though the tell-tale flow looked fine.

Likely caused by... only flushing using the flushing port with the engine not running. IOW, not flushing using a muff with the engine running. Suspect it's because the thermostat probably doesn't open when flushing with the engine off.

Probably exacerbated by not running the thing very often. We've only got about 17 hours on the outboard, over the last 4 years. (Since we lost the big dog, we don't need to go ashore as religiously.)

Salt-Away didn't work, once we were at the point where we discovered the issue.

-Chris
__________________
Selby Bay, South River, Chesapeake Bay, USA.
ranger42c is offline   Reply With Quote
Old 22-01-2019, 14:43   #13
Registered User

Join Date: Sep 2007
Location: Queensland, Australia
Boat: None at present--between vessels. Ex Piver Loadstar 12.5 metres
Posts: 803
Re: Mercury 5hp no water flow

I had the same problem with a Yamaha 3.5 hp engine.

I thought there might be something that had got past the impeller and was obstructing the water outlet. Unfortunately that was not the case for me. Maybe it is for you. Lets hope so.

I stripped the motor and opened it up, finding no protective coating on the inside of the water chambers, and the bare aluminium had corroded and blocked the waterway where it exits. I replaced the thermostat while I was at it. I put it all back together after cleaning it thoroughly, and it worked fine. I had also cleaned the carburetor and fuel pump while I was at it. If you have the engine on a bench, you might as well test and check everything.


Next time I have it apart I will properly coat all the aluminium surfaces in contact with cooling sea water. I will do some research as to the most suitable coating--paint, epoxy, poly urethane etc.
Mike Banks is offline   Reply With Quote
Old 22-01-2019, 14:48   #14
Registered User

Join Date: Nov 2017
Location: Five Points AL
Boat: SeaFox Voyager 256 25 foot
Posts: 5
Re: Mercury 5hp no water flow

I use a short piece of weedeater string to clean the tube. Works great and does not punch thru the tube.
Randall M is offline   Reply With Quote
Old 22-01-2019, 15:00   #15
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,887
Re: Mercury 5hp no water flow

Quote:
Originally Posted by ranger42c View Post
Suzuki DF15A, same as yours except horsepower I guess.

The red light came on and it went into limp mode, even though the tell-tale flow looked fine.

Likely caused by... only flushing using the flushing port with the engine not running. IOW, not flushing using a muff with the engine running. Suspect it's because the thermostat probably doesn't open when flushing with the engine off.

Probably exacerbated by not running the thing very often. We've only got about 17 hours on the outboard, over the last 4 years. (Since we lost the big dog, we don't need to go ashore as religiously.)

Salt-Away didn't work, once we were at the point where we discovered the issue.

-Chris


Yours is I believe the second Suzuki I have heard that has had this issue.
The 9.9, 15 and 20 Suzuki are I believe the same motor, computer is the difference, although I have heard that there is a throttle restrictor on the 15. I didnít think that though, I thought it was just computer.
__________________

a64pilot is offline   Reply With Quote
Reply

Tags
mercury, water

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
At My Wit's End with My 2001 Mercury 5hp Two-Stoke Outboard ! Janae Engines and Propulsion Systems 20 11-07-2017 20:35
5hp vs 2.5hp on cal 27...Need your help boatsail Monohull Sailboats 9 16-07-2012 13:56
2004 Mercury 5HP 5M Tom Stewart Engines and Propulsion Systems 2 20-01-2012 10:48
5hp Mercury N52129 Engines and Propulsion Systems 3 10-09-2010 09:48
Alternator Install Into a Mercury 5hp unbusted67 Engines and Propulsion Systems 3 19-06-2010 06:50



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 16:40.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.