Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-07-2016, 12:21   #16
Registered User

Join Date: Apr 2014
Boat: Beneteau Oceanis 45
Posts: 173
Re: Favorite fuel priming pump?

The risk from an inline electric fuel pump is a runaway engine, which can be hard to shut down. When the engine mounted mechanical pump gets a hole in the rubber pump diaphragm the electric pump pressure will send fuel into the engine crankcase. With enough diesel in the crankcase you can end up with a runaway engine. You have to cut off the air supply to stop it, which can be a bit scary with the engine screaming above redline.

Eventually developing a hole in the diaphragm is not all that uncommon, given enough hours. If you run an electric pump you should periodically replace your engine mounted pump to reduce the chances of a runaway engine.

Without an inline electric pump, the engine simply stops or sputters when a hole develops in the mechanical pump diaphragm.

I didn't make this up. I learned about this while taking an advanced diesel repair course at a maritime school.

Fuel bulbs are not ABYC compliant for use on an inboard. However my last boat had one. I agree they are handy.
__________________

__________________
SteveInMD is offline   Reply With Quote
Old 28-07-2016, 12:32   #17
Registered User

Join Date: Apr 2015
Posts: 16
Re: Favorite fuel priming pump?

I've been considering an electric inline pump for priming as needed but had a question for those of you who do this. Do you valve the electric pump into the feed line to the racors when needed but then reposition the valves to allow a direct flow from the tank to the racors after priming is complete or is the electric plumbed directly into the feed line and just shut down when not needed for priming???
__________________

__________________
patfarrell1949 is offline   Reply With Quote
Old 28-07-2016, 13:07   #18
Registered User

Join Date: Jan 2015
Location: SoCal
Boat: Formosa 30 ketch
Posts: 349
Re: Favorite fuel priming pump?

I just bought a cheap 2psi inline pump, you can blow through it in the foreward direction, so I think I'll just plumb it into the line before the filters, and only turn it on when it's needed to prime the system.
__________________
Bill Seal is offline   Reply With Quote
Old 28-07-2016, 13:12   #19
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,024
Re: Favorite fuel priming pump?

Quote:
Originally Posted by Bill Seal View Post
I just bought a cheap 2psi inline pump, you can blow through it in the foreward direction, so I think I'll just plumb it into the line before the filters, and only turn it on when it's needed to prime the system.

That is the idea of a primer pump, no valves etc, just don't run it unless your bleeding air out of the filters you just replaced
__________________
a64pilot is offline   Reply With Quote
Old 28-07-2016, 13:16   #20
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,024
Re: Favorite fuel priming pump?

Reference mechanical diaphragm pumps, they can in fact bleed fuel into the engine crankcase if the diaphragm fails and cause an engine run away with no electric pump in the picture, it has happened before. I think ask Zeehag
If I was going to run an electric fuel pump, it would be in place of and not along with the mechanical diaphragm pump.
Primer bulbs will rot out and fail, I think there are photos of some on the Compass Marine website (AKA Mainsail)

Link to failed primer bulb, I don't think Mainesail would mind
http://www.pbase.com/mainecruising/image/145237549
__________________
a64pilot is offline   Reply With Quote
Old 28-07-2016, 13:18   #21
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Favorite fuel priming pump?

Quote:
Originally Posted by a64pilot View Post
just don't run it unless your bleeding air out of the filters you just replaced
Why ??
__________________
Guy is offline   Reply With Quote
Old 28-07-2016, 15:05   #22
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,024
Favorite fuel priming pump?

Quote:
Originally Posted by Guy View Post
Why ??

Well couple of reasons, there is no need, it's not doing anything except wearing itself out, secondly if a leak downstream of the electric pump develops, you now have fuel leaking , maybe spraying in the boat.

Now if you want to replace your mechanical with an electric, I can see the logic there, just wire it so the pump runs with the key on, and if you want to bleed the fuel filters, turn on the key, you have to put up with the low oil pressure alarm, but as it should only be a short while it ought to be OK.
As long as your pump supplies enough fuel at the right pressure, only down side I see is you now have an engine that requires electricity to run. But replacements are cheap and easy as opposed to mechanicals, they may not be nearly as cheap.


Sent from my iPad Pro using Cruisers Sailing Forum
__________________
a64pilot is offline   Reply With Quote
Old 28-07-2016, 15:54   #23
Registered User
 
leftbrainstuff's Avatar

Join Date: May 2011
Location: San Francisco and Australia
Boat: Liberty 458
Posts: 1,978
Re: Favorite fuel priming pump?

We have a Racor P Series primary pump and a walbro backup. Both plumbed in parallel.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app
__________________
leftbrainstuff is offline   Reply With Quote
Old 28-07-2016, 16:01   #24
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Favorite fuel priming pump?

[QUOTE=a64pilot;2177063]ey, you have to put up with the low oil pressure alarm, but as it should only be a short while it ought to be OK.
As long as your pump supplies enough fuel at the right pressure, only down side I see is you now have an engine that requires electricity to run.


I couldn't stand the alarm so there is a power switch just for the pump when you need it. I figured if I could get the engine started there is enough juice to run one of those little pumps off solar wind and batts for a good while.
__________________
Guy is offline   Reply With Quote
Old 28-07-2016, 16:40   #25
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,024
Favorite fuel priming pump?

Way IP wired mine from the factory is you have to have the key on, then you can turn the switch on and run the electric priming pump. Has a placard that says to only use pump when priming, do not leave on.
It was a Lucas pump, very hard to find and stupid expensive, so I just tossed it when I installed the dual Racor set up, it took maybe all of 1 min to completely fill both completely empty Racors so I decided I didn't need the electric pump.
The mechanical pump works I believe just like most automobiles, an arm rides on a cam lobe and this actuates the pump.
Trick is the engine can stop with the arm pushing the pump at the top of its stroke so you manually pumping the lever won't do anything much so if you feel no resistance on the lever, you may have to turn the crank a little to get the pump so you can get a full stroke with the manual lever.


Sent from my iPad Pro using Cruisers Sailing Forum
__________________
a64pilot is offline   Reply With Quote
Old 28-07-2016, 18:26   #26
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Favorite fuel priming pump?

[QUOTE=a64pilot;2177137]
It was a Lucas pump, very hard to find and stupid expensive,

Just like the one in my MG? Holy crap, I bet the new totally encapsulated pumps are unlimited life. If I understand them, they are a spring loaded solenoid. Using diesel as lube, they should never quit.
__________________
Guy is offline   Reply With Quote
Old 28-07-2016, 19:17   #27
Registered User

Join Date: Apr 2016
Posts: 18
Re: Favorite fuel priming pump?

Outboard squeeze bulb. Works great. Smaller engines you can just put it in the fuel line or do this
SMX Complete Squeeze Bulb Priming Kit - Seaboard Marine
__________________
sean9c is offline   Reply With Quote
Old 28-07-2016, 19:53   #28
Registered User
 
Kijit's Avatar

Join Date: Jun 2010
Location: Virginia
Boat: Wauquiez Centurion 41
Posts: 53
Send a message via Skype™ to Kijit
Re: Favorite fuel priming pump?

Quote:
Originally Posted by belizesailor View Post
I have bulbs installed in line, work fine. Dead simple install.

You really dont need to move that much fuel to prime a small engine filter system. A few pumps is all it usually takes on mine (Volvo MD2020, RACOR FG500 filter).
I do the same. Works great.

Sent from my SCH-I545 using Tapatalk
__________________

__________________
Gerhard
S/V KIJIT
Wauquiez Centurion 41
Kijit is offline   Reply With Quote
Reply

Tags
fuel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Raw water pump not priming at idle RPM nigel1 Engines and Propulsion Systems 18 18-05-2016 10:28
MD7A water pump not priming terah Engines and Propulsion Systems 21 18-04-2015 10:24
Electric Priming /Back up Fuel Pump sailorchic34 Engines and Propulsion Systems 32 17-12-2014 13:30
Self-Priming Pump won't Prime! chad.lawie Plumbing Systems and Fixtures 12 29-10-2014 06:24
Fuel Priming Pump DeepFrz Engines and Propulsion Systems 10 04-06-2008 13:02



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 21:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.