Universal M25 Overheating Issue - Page 2 - SailNet Community
Reply
 
LinkBack Thread Tools
post #11 of 14 Old 10-28-2012 Thread Starter
Junior Member
 
Join Date: Oct 2012
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: Universal M25 Overheating Issue

Bingo! Looks like the mixing elbow did the trick. Took her out yesterday and was able to get up to 2300 RPM with the engine temp steady at about 170. Though I did have to back down to 2100 as the exhaust was putting out some black smoke at that high.
natew82 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #12 of 14 Old 10-12-2016
Junior Member
 
Join Date: Oct 2016
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: Universal M25 Overheating Issue

did you ever fix your over heating issue?

sen
seancox is offline  
Quote Quick Reply Share with Facebook
post #13 of 14 Old 10-12-2016 Thread Starter
Junior Member
 
Join Date: Oct 2012
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: Universal M25 Overheating Issue

Yes I did. It was a combination of things. The mixing elbow was very clogged, it eventually just got replaced rather than cleaned. After fixing that and changing out the water pump with the grease cup-less model which has a higher flow rate we solved the overheating issue. What we also found was that since it was over heating above 1800RPM the previous owner had installed a much higher pitched prop to run at 5-6knots at 1600RPM, so it was way over pitched and almost lugging the engine and kept the engine from going over 2000RPM which likely contributed to the further clogging of the mixing elbow. We ended up installing a properly sized prop and there after could get the engine up to about 2800 RPM. We cruised all around Mexico and Central America after that in waters upwards of 100 degrees and had zero problems with cooling, we ran the engine sometimes for 3-4 days straight at 2200RPM and not a blip on the temp gauge.
natew82 is offline  
Quote Quick Reply Share with Facebook
 
post #14 of 14 Old 10-12-2016
Learning the HARD way...
 
eherlihy's Avatar
 
Join Date: Jan 2007
Location: Boston / Ft Myers Area
Posts: 5,309
Thanks: 272
Thanked 189 Times in 185 Posts
Rep Power: 11
 
Re: Universal M25 Overheating Issue

A LOT of M25s shipped with a 2Ĺ" heat exchanger. This H/X is undersized for the M25.

Even more M25s have the hot water heater plumbed in line with the main cooling circuit. Once the water in the hot water tank is hot, this adds another source of heat, and usually a restriction to the main cooling circuit.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

USCG Licensed OUPV Captain, ASA 101/103/104/105/106/118 Instructor - Also certified in Marine Electrical Systems


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
eherlihy is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Universal Diesel M25X overheating glassdad General Discussion (sailing related) 6 12-15-2011 01:41 PM
overheating M25 BarryL Diesel 5 06-12-2010 09:28 PM
Overheating Universal 5411 JohnBassett Gear & Maintenance 20 05-20-2009 12:54 PM
Universal M25 Overheating - Puzzling symptoms endreholen Gear & Maintenance 17 12-10-2008 01:07 PM
Universal M2-12 Overheating phallo153 Gear & Maintenance 10 01-02-2008 11:53 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome