Return to the home page...

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

Thread Tools Display Modes
  #26   IP:
Old 04-06-2012, 01:27 AM
hanleyclifford hanleyclifford is offline
Join Date: Mar 2010
Posts: 6,860
Thanks: 141
Thanked 221 Times in 183 Posts

In 99% of cases Neil is right about not needing the override circuit from the "R" terminal on the solenoid to get the fuel pump running before oil pressure is achieved. In fact on my boat I don't want fuel pump or ignition until at least 7 psi oil pressure is attained. FWIW, sometimes the "R" terminal is used to provide a coil resistor override to "goose" the voltage to the ignition during cranking.
Reply With Quote
  #27   IP:
Old 05-25-2023, 02:44 AM
magi magi is offline
Frequent Contributor
Join Date: Dec 2021
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
OPSS Jumped Out

How bad of an idea is running with the OPSS jumped out ?
Reply With Quote
  #28   IP:
Old 05-25-2023, 07:55 AM
msmith10's Avatar
msmith10 msmith10 is offline
Afourian MVP
Join Date: Jun 2006
Location: Columbus, Ohio
Posts: 473
Thanks: 19
Thanked 62 Times in 46 Posts
The purpose of the OPPS is to turn off the fuel pump if the engine is not running, thus preventing the pump from forcing fuel into the carb and potentially spilling into the bilge. If I were away my home port and the OPPS malfunctioned, I would bypass it to get home, then fix it. I would not leave it bypassed as this would create a potentially unsafe condition, would certainly void the insurance, and is just an unseamanlike thing to do.
It's such an easy fix- screw out screw in.
Mark Smith
1977 c&c30 Mk1 hailing from Port Clinton, Ohio
Reply With Quote
  #29   IP:
Old 05-25-2023, 07:17 PM
joe_db's Avatar
joe_db joe_db is online now
Afourian MVP
Join Date: May 2009
Posts: 4,386
Thanks: 49
Thanked 981 Times in 690 Posts
Originally Posted by ndutton View Post
It's my opinion the override adds unnecessary wiring complexity to a basic A-4. There is ample residual fuel in the carb bowl to get the engine started without any help from the fuel pump. Once started the oil pressure rises so quickly it seems the fuel pump starts instantly (I have a fuel pump indicator light on my engine panel so I keep a close eye on it).

If you're a keep it simple sort, I'd avoid the start switch override altogether. Simpler to wire in the first place, simpler to troubleshoot later.
I have a manual button for the override. If I have run the fuel out after shutdown, I use it. If the engine was just turned off still showing fuel pressure, it is not needed.
Joe Della Barba
C&C 35 MK I
Maryland USA
Reply With Quote
  #30   IP:
Old 05-26-2023, 03:48 PM
capnward's Avatar
capnward capnward is offline
Afourian MVP
Join Date: Aug 2012
Location: Deer Harbor WA
Posts: 335
Thanks: 41
Thanked 147 Times in 107 Posts
More mechanical fuel pump advocacy

Just a reminder, if you have a mechanical fuel pump (there I go again!), there is no need to override or bypass anything electrical to get fuel pressure with the engine off. You just manually pump the bail underneath the pump until the resistance disappears and your fuel pressure gauge reads 3 or so. This way the engine will start sooner and not have to crank for a while to get fuel from the tank to the carb. And as Joe said, if you have been running recently there will be adequate fuel in the carb to start.
Reply With Quote

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
oil pressure safety switch morgan_out_island Fuel System 5 05-25-2023 11:53 AM
Wiring of Oil Pressure Safety Switch forcenine Electrical 25 07-01-2021 09:57 AM
Oil pressure safety switch Marty Levenson General Interest 16 10-12-2011 01:30 PM
oil pressure safety switch ramon Safety 7 05-18-2010 11:34 AM
wiring question- oil pressure safety switch? msmith10 Electrical 2 09-10-2006 09:03 AM

All times are GMT -4. The time now is 10:04 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2023 Moyer Marine Inc.

All Rights Reserved