Return to the home page...

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

Reply
 
Thread Tools Display Modes
  #26   IP: 73.134.199.19
Old 03-15-2017, 03:59 PM
macgyro macgyro is offline
Frequent Contributor
 
Join Date: Sep 2014
Posts: 8
Thanks: 0
Thanked 0 Times in 0 Posts
Similar symptoms, no exhaust blockage

Hi guys,

I know this thread has been inactive for a while, but the symptoms described were exactly what I was experiencing at the end of last season. My RPM wouldn't go above 1800 RPM and it sounded like the engine was flooding/bogging down. It started funny, sometimes with no choke, sometimes it wouldn't run without choke, but never ran quite right.

I tried different twists of the mixture control jet screw thing on the aft end of the carb, different choke settings, etc. Then I pulled the plugs, and the forward 3 were black and sooty with the aft-most slightly white.

I found this thread and, the next day, removed my exhaust hoses to try to find the blockage. All of the hoses were fine, so I blew into the muffler and launched a fountain of glycol all over the cockpit of the boat. Then I removed the dry exhaust section from the manifold. No blockages anywhere, including the thru-hull on the transom (Ericson 32).

Could the exhaust blockage be in the manifold?

Part 2:
Early last season, the engine started to overheat (200 degrees) and I installed the cooling bypass line with the shutoff valve and used it with the bypass valve mostly closed. Then, the engine ran too cool and would rarely get up to temperature but was still running fine (up to about 2200 RPM on my tach. I don't think the tach is set right) I was nervous about running for a long time with the valve completely open in case I forgot to monitor the temperature and it climbed again. I got a new thermostat this winter, so I'm hoping to keep the valve open and it will work.

That was a long story, but since I ran the engine for most of the season too cool, I'm wondering if that could have fouled the plugs enough alone to cause my symptoms without excessive exhaust backpressure?

If anyone's still out there, do you have any ideas?

Thanks!

Dean
Reply With Quote
  #27   IP: 97.93.89.70
Old 03-16-2017, 11:07 AM
Dave Neptune Dave Neptune is online now
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Grove, Oklahoma
Posts: 4,704
Thanks: 617
Thanked 945 Times in 635 Posts
Cool

Dean, I suggest a new thread. It sounds like one of two things or possibly both. First the idle screw will only affect the idle circuit and it sounds like the carb is running way rich to cause sooty plugs. A good look at the carb is in order and a thorough cleaning.
Second is timing. Timing can be way off if the points (if still equipped with them) and the cam are worn down a likely senarior due to the age of the motor. Check the "dwell" not the gap in these old engines!!!! Be sure you have a good "blue" spark and set the timing or just try a bit of "advance" to see if it helps.
The right fuel mix (carb)~good blue spark~and the spark being delivered at the right time (timing) equals a good running engine!!
Other notes connected to the above. Make sure the centrifugal advance is working inside the distributor~ a fresh cap and rotor~fresh plugs~plug wires in good shape. Also do a visual to be sure the choke is fully opening and closing.
I don't see how the manifold itself could create a blockage inside.

Dave Neptune
Reply With Quote
  #28   IP: 145.239.2.231
Old 11-24-2020, 09:40 AM
wakemutant wakemutant is offline
Member
 
Join Date: Oct 2020
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
How does one inspect the various pipes in the exhaust line to ensure no obstructions? I have a good old stand pipe muffler with the coolling water ejection BRAIDED LINE (8 PLY) SEA STORM - MZBL8YW-XXX at the top of the standing system as is common. Should I just start yanking things apart? What should I be looking for?

Last edited by wakemutant; 12-04-2020 at 04:47 AM.
Reply With Quote
  #29   IP: 172.58.19.76
Old 11-24-2020, 10:04 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,475
Thanks: 188
Thanked 2,011 Times in 1,330 Posts
Quote:
Originally Posted by wakemutant View Post
How does one inspect the various pipes in the exhaust line to ensure no obstructions?
Exhaust back pressure gauge.
__________________
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
The Following User Says Thank You to ndutton For This Useful Post:
Ando (11-25-2020)
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
Sooty Plugs Unregistered Guest Ignition System 3 03-26-2007 06:22 PM
No Spark Now? but sooty plugs before? Capt.Terry Ignition System 10 02-10-2007 09:19 AM
MMO or Cool temp contributing to fouled plugs jkenan Troubleshooting 2 11-21-2006 06:34 AM
more fouled plugs bill wright Troubleshooting 3 12-15-2005 08:32 AM
Blue Smoke and 2 oily plugs Jacob Wenegrat Troubleshooting 3 08-26-2005 09:58 AM


All times are GMT -4. The time now is 10:54 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2022 Moyer Marine Inc.

All Rights Reserved