View Thread
Before Posting, Please Read Our Posting Guidelines Below.

1. Use the full 4 digit year for everything you are asking your question about. Example: 1962, 1988, 2000, 2011
2. Include the correct name of your Whaler model. Example: Montauk 17, Montauk 170, Outrage 26, Outrage 260
3. Include the length when necessary. Example: 16, 17, 18, 20, 22
4. Do not post your email address anywhere on this site as it is already in your user profile.

 Print Thread
1985 Mercury 50hp 4cyl potential cooling problem
rockinhitz34
#1 Print Post
Posted on 04/24/18 - 9:37 AM
Member
Personal Page

Posts: 105
Comments: 0
Joined: 12/17/15

Took the motor out to start today and she ran great. Replaced impeller and gaskets yesterday, had a steady stream of water from the tell tale. I ran the motor for 15 minutes at idle and then shifted into fwd and reverse just to test. all seemed good. Tell tale water wasn't very warm which could be because today isn't very hot (~60F outside). However, I noticed that the upper exhaust port didn't have much water mist coming out.

I pulled the plugs to check them and they seemed OK, yet on the 3 and 4 cyl outside there was emulsified fuel/water on the case and outside of the plugs. Im wondering if I could have a head gasket/thermostat/cooling channel issue. Is there a good way to test powerhead temperature with a thermometer laser thingy? I have a seloc manual but they don't list normal operating temperatures. I just want to make sure I don't have a cooling problem before I run at speed in the water this summer.

Thanks, I appreciate the help.


1969 13' "Super Sport", 1985 50hp Merc
 
fitz73222
#2 Print Post
Posted on 04/25/18 - 9:48 AM
Member

Posts: 67
Comments: 0
Joined: 02/23/16

rockinhitz34 wrote:
Took the motor out to start today and she ran great. Replaced impeller and gaskets yesterday, had a steady stream of water from the tell tale. I ran the motor for 15 minutes at idle and then shifted into fwd and reverse just to test. all seemed good. Tell tale water wasn't very warm which could be because today isn't very hot (~60F outside). However, I noticed that the upper exhaust port didn't have much water mist coming out.

I pulled the plugs to check them and they seemed OK, yet on the 3 and 4 cyl outside there was emulsified fuel/water on the case and outside of the plugs. Im wondering if I could have a head gasket/thermostat/cooling channel issue. Is there a good way to test powerhead temperature with a thermometer laser thingy? I have a seloc manual but they don't list normal operating temperatures. I just want to make sure I don't have a cooling problem before I run at speed in the water this summer.

Thanks, I appreciate the help.


 
fitz73222
#3 Print Post
Posted on 04/25/18 - 9:48 AM
Member

Posts: 67
Comments: 0
Joined: 02/23/16

rockinhitz34 wrote:
Took the motor out to start today and she ran great. Replaced impeller and gaskets yesterday, had a steady stream of water from the tell tale. I ran the motor for 15 minutes at idle and then shifted into fwd and reverse just to test. all seemed good. Tell tale water wasn't very warm which could be because today isn't very hot (~60F outside). However, I noticed that the upper exhaust port didn't have much water mist coming out.

I pulled the plugs to check them and they seemed OK, yet on the 3 and 4 cyl outside there was emulsified fuel/water on the case and outside of the plugs. Im wondering if I could have a head gasket/thermostat/cooling channel issue. Is there a good way to test powerhead temperature with a thermometer laser thingy? I have a seloc manual but they don't list normal operating temperatures. I just want to make sure I don't have a cooling problem before I run at speed in the water this summer.

Thanks, I appreciate the help.


 
fitz73222
#4 Print Post
Posted on 04/25/18 - 9:58 AM
Member

Posts: 67
Comments: 0
Joined: 02/23/16

There is nothing wrong with your engine from a cooling perspective. The engine does not have a thermostat by design so the water out of the tell tale will always be relatively cool. The above water exhaust relief rarely has an water coming out of it except an occasional spit of water unlike the larger in- line 6 cylinder version. To check temperature, hold your hand on the exhaust plate on the port side of the engine while running in the water and it should be cool to slightly warm. These engines run fairly cold. You should always be able to hold you hand on that plate without any discomfort. Your description of emulsified oil and water on the exterior of the block cover needs further explanation. I have seen anti-corrosion sprays when subject to moisture take on a milky appearance that resembles what you are describing. If there is no water leaking around the plug and there is no water on the firing surface of the plug. I would not worry about it.

 
rockinhitz34
#5 Print Post
Posted on 04/26/18 - 11:37 AM
Member
Personal Page

Posts: 105
Comments: 0
Joined: 12/17/15

fitz73222 wrote:
There is nothing wrong with your engine from a cooling perspective. The engine does not have a thermostat by design so the water out of the tell tale will always be relatively cool. The above water exhaust relief rarely has an water coming out of it except an occasional spit of water unlike the larger in- line 6 cylinder version. To check temperature, hold your hand on the exhaust plate on the port side of the engine while running in the water and it should be cool to slightly warm. These engines run fairly cold. You should always be able to hold you hand on that plate without any discomfort. Your description of emulsified oil and water on the exterior of the block cover needs further explanation. I have seen anti-corrosion sprays when subject to moisture take on a milky appearance that resembles what you are describing. If there is no water leaking around the plug and there is no water on the firing surface of the plug. I would not worry about it.


Thanks for the reply. I cant tell if the water jacket cover is leaking. There was no water on the cylinder side of the plug, only on the exterior. My plugs from last year had some serious corrosion on the exterior. Im thinking that the water jacket gasket might be the culprit. When I run the motor again next week Im going to test temp as you have described and see if I can see any water leaking around the plugs from the water jacket cover.

In terms of degrees in Fahrenheit, whats a good approximation of operating temperature? Thinking in the 130-150 degree range.
Thanks again!


1969 13' "Super Sport", 1985 50hp Merc
 
fitz73222
#6 Print Post
Posted on 04/27/18 - 2:13 AM
Member

Posts: 67
Comments: 0
Joined: 02/23/16

Believe it or not, you'll be lucky to see 100 degrees, they really run cool since there is no thermostat. Don't be surprised that your lower plug corrosion is nothing more than the plugs getting occasionally wet from backwash when you slow down coming off of a plane. I've seen lots of engines with lower one or two plugs with corrosion like that particularly in salt water.

 
Jump to Forum:
Bookmark and Share
Today's Date & Time
November 22, 2024 - 11:16 AM
Visit our Sponsors
Wm. J. Mills and Co. - Boston Whaler Canvas


Specialty Marine - Parts and Accessories


Nauset Marine - Whaler Parts and Accessories


Carver Covers - The Best Covers Under The Sun



Click on logo to visit site
View all Sponsors Here
Users Online
Welcome
AuntiesMontauk
as the newest member

· Guests Online: 3
· Members Online: 0
· Total Members: 50,390
Login
Username

Password

Remember Me


Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Top 5 Models Posted
· Montauk 17 1,638
· Sport 13 1,366
· Outrage 18 556
· Nauset 16 402
· Sport 15 365

View all Models Here
Render time: 0.20 seconds Copyright WhalerCentral.com © 2003-2024 86,542,019 unique visits