Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Exhaust System

Reply
 
Thread Tools Display Modes
  #1   IP: 72.234.190.214
Old 01-30-2019, 12:43 AM
deantheking101 deantheking101 is offline
New Member
 
Join Date: Oct 2017
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Exhaust Manifold Corrosion

I have a 1975 C30 with a large deal of corrosion on the most forward manifold stud to the point where it is dropping into the air intake. I took some pictures before and after i cleaned it up with a wire brush.

Second the motor when it gets hot after running for 3+ hours starts to smoke pretty badly. I believe mostly out of the tube where you add the oil. However some smoke also coming out of the manifold also. The temp guage does not work......

I did a compression test today. The most forward cylinder was 50 (i checked it twice) the other 3 were all 80-85.

I spoke with Ken at Moyers and sent him this same email and will be talking to him soon but wanted to get some other opinions on the best course of action. This summer i plan on doing a inner island 3-4 week trip in Hawaii and want well running motor. Buying a rebuilt one is a option.

Thanks in advance.

https://www.youtube.com/watch?v=rCdZ...ature=youtu.be

https://www.youtube.com/watch?v=tWEj...ature=youtu.be
Attached Images
     
Reply With Quote
  #2   IP: 32.211.28.40
Old 01-30-2019, 07:48 PM
Al Schober's Avatar
Al Schober Al Schober is offline
Afourian MVP
 
Join Date: Jul 2009
Location: Uncasville, CT
Posts: 2,002
Thanks: 16
Thanked 578 Times in 405 Posts
First, you may have a slight leak where that manifold stud screws into the block. I'd try removing the manifold then cleaning and reseating all 3 studs. I'd install a new stud/nut and trash the rusty ones. While you've got them out, check the wall thickness of the block at all 3 studs - see what you've got left. This is low cost - might not even need a new manifold gasket but I'd get one just in case.
Second, compression. Those numbers and the smoke suggest to me worn piston rings. Don't know the history of the engine but it could be time for new rings - they DO wear out. May not be a big deal - bearings and the pistons themselves may be fine.
If you don't have the Moyer Manual, buy one. Details engine disassembly, overhaul, reassembly. Basically, you're going to remove the engine from the boat, remove transmission, head, and oil pan. This will allow you to remove the pistons, replace the rings, then reassemble. Based on my experience, you will find NO ridge at the tops of the cylinders worth reaming. Reassemble with new rings and you could be done - good for another 20 years. Also recommend changing the aft transmission oil seal.

Last edited by Al Schober; 01-30-2019 at 07:54 PM.
Reply With Quote
The Following User Says Thank You to Al Schober For This Useful Post:
TimBSmith (09-23-2020)
  #3   IP: 24.152.132.140
Old 01-30-2019, 09:18 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
Part of the smoke problem may be the orientation of the backfire flame arrester. However, if there is budget for a Moyer rebuilt, you can't go wrong.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #4   IP: 137.103.82.194
Old 01-31-2019, 07:48 AM
joe_db's Avatar
joe_db joe_db is online now
Afourian MVP
 
Join Date: May 2009
Posts: 4,474
Thanks: 49
Thanked 1,026 Times in 721 Posts
If you have the cash, I wouldn't hesitate for a second to get a Moyer rebuild.
Reply With Quote
  #5   IP: 69.112.56.174
Old 01-31-2019, 10:15 AM
jwmurphy jwmurphy is offline
Senior Member
 
Join Date: Oct 2012
Posts: 19
Thanks: 0
Thanked 3 Times in 3 Posts
General question:
I noticed in Dean's pictures that the scavenger tube appears to be cut/disconnected. Is this a fuel safety concern?
Reply With Quote
The Following User Says Thank You to jwmurphy For This Useful Post:
thatch (01-31-2019)
Reply

Thread Tools
Display Modes

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
NOTHING coming out of the exhaust manifold pdecker Cooling System 9 07-05-2015 03:06 PM
Exhaust manifold problem re-post w/pic's wmmulvey Exhaust System 26 07-20-2012 10:49 AM
manifold water leak v/s exhaust waterjacket leak, or BOTH alkaid Exhaust System 1 08-23-2005 02:36 PM


All times are GMT -4. The time now is 12:44 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved