50 HP Perkins Overheating Problem - SailNet Community

   Search Sailnet:

 forums  store  

Quick Menu
Boat Reviews  
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Hatches and Portlights
Interior And Galley
Marine Electronics
Other Items
Plumbing and Pumps
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here

Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
Old 07-26-2006
Junior Member
Join Date: May 2006
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Freedom777 is on a distinguished road
50 HP Perkins Overheating Problem

My 50 HP Perkins (1980 model) has been acting up and seems to bog down immediately. The performance of the engine as decreased over the last 6 months. The temperature guage goes to redline and I don't seem to be making any headway - 4-5 kts at full throttle. I just had a mechanic look the boat over (sea trial) this afternoon and he said the water intake wasn't blocked and the engine seemed to be running correctly. A new water pump was installed and the intake is clear. There are no coolant leaks either. He suggests taking out and cleaning (or replacing) the heat exchanger. It this a good idea? Estimated charge $1,000+. If this is the problem, does anyone know where to find a mechanic near Tarpon Springs/Clearwater, FL that charges less than $100 per hour. Thanks.
Reply With Quote Quick reply to this message Share with Facebook
Old 07-26-2006
Eleanna's Avatar
Join Date: Jul 2006
Location: Miami
Posts: 53
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
Eleanna is on a distinguished road
You might want to look at my thread from last week. I had similar problems. And my solution was the cutlass bearing that caused the overheating,decreased rpm and vibrations in the rudder.

Reply With Quote Quick reply to this message Share with Facebook
Old 07-26-2006
Join Date: Feb 2006
Posts: 64
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 10
DynaMeme is on a distinguished road
Overheating and Overcharging

Perkins 4-108s and 4-107s are susceptible to the cooling water discharge into the exhaust being blocked by carbon build up. This will not be easily detected by watching the exhaust water flow. If the engine installation is older than 5 years this is a good thing to check. Removing and replacing the hose is tedious but not hard. Cleaning the exhaust water entry port (into the elbow) can be done with a shotgun cleaning brush. Wear eye protection.

One risk is this carbon build up can also be sealing corrosion leaks in this area so cleaning out the carbon (a must) may lead to the need to replace the elbow. This is not easy. It does not come free from the manifold willingly. I had to remove the manifold from the engine and put it in a very big vise, torch it to get it running temp hot and then persuaded the elbow with a 2# engineer's hammer.

But even before that, one of the most common reasons for over-heating is zinc pencil debris accumulating in the front end of the heat exchanger. When you installed new pencil zincs, did you fish out the old debris? If not you may have several years worth choking off the water flow. If the heat exchanger needs cleaning, treat it like a radiator cleaning job. A short mild acid bath followed by a gentle push through the tubes with a welding rod at least 1/32" smaller than the tube inside diameter. You will need to replace the endcap gaskets/seals.

Lastly a rebuilt/new heat exchanger is $3-400. Replacing it it is an hour job at most -- 4 bolts out then in. Four hose clamps off then on. It is dirty and awkward but not difficult. Anybody who wants more than $600 for the job parts included is overcharging.
Reply With Quote Quick reply to this message Share with Facebook

Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


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

Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Overheating Perkins 4-108 Eleanna Gear & Maintenance 13 07-24-2006 06:59 AM
GROCO-HF Flush-Dry Problem Ronn Gear & Maintenance 1 07-03-2006 03:26 PM
Perkins 4-108 overheating nelsonsmoody Gear & Maintenance 10 06-27-2006 03:24 PM
Engine Oil Pressure Problem msamelso Gear & Maintenance 2 02-20-2001 06:25 PM
Ericson- Mast Compression Problem Jeff_H Gear & Maintenance 2 12-31-2000 09:30 PM

All times are GMT -4. The time now is 09:15 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.