Elect vs. Mech lift pump

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Dixie Life

Senior Member
Joined
Feb 4, 2011
Messages
213
Location
USA
Vessel Name
Aku Uka
Vessel Make
43’ DeFever
Has anyone changed their lift pump to an electrical pump. I'm in the process of changing mine and I saw somewhere a guy installed an electrical one on a FL120 instead of the original mechanical. Has any of you guys tried this? No doubt the original pump is more dependable but maybe an electrical for backup situation. Ideas?
 
I replaced my mechanical pump on my Perkins 20 years ago and have not had a problem since. Installed a new electric at 15 years and kept the old one as a backup in the parts bin.
 
Has anyone changed their lift pump to an electrical pump. I'm in the process of changing mine and I saw somewhere a guy installed an electrical one on a FL120 instead of the original mechanical. Has any of you guys tried this? No doubt the original pump is more dependable but maybe an electrical for backup situation. Ideas?

I might be "that" FL 120 guy. This is not an uncommon installation. I used a Walbro FRB 13, a pump with a good rep for longevity. The mechanical pump is still in place. Some day I will get around to removing it and installing a blockoff plate. As for the mechanical pump no doubt being more reliable, that may not be true. Plus, when the diaphragm on the mechanical pump ruptures, diesel fuel gets pumped into the lube oil sump which is most definitely not a good thing. If the electric pump fails, it just stops pumping. Keep a spare and sleep well. I have a brand new mechanical pump in my spares inventory if anyone wants one at a reduced price.
 
I switched to a Walbro electric on my Lehman 120 2 years ago. Removed the mechanical pump and covered the whole. Runs like a charm and very easy to replace if it dies.
 
I have an electric pump plumbed in as a backup and for priming (if needed).
 

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I have an electric pump plumbed in as a backup and for priming (if needed).

:thumb::thumb: It makes priming a snap.

We have also used ours recently after installing the new fuel tanks and rebuilt engine. I had a small air leak during a passage. Every 4-8 hours the engine would be fuel starved. I turned on the electric fuel pump, bled the system and we had no issues for the rest of the trip. When we got to the anchorage, I was able to find and fix the problem.
 
I have electric pumps similar to the photo on each of my Detroit mains. Their rating is about the same as the mechanical gear pump. I only use them for filling my secondary filter, but leave them in place for emergency use. The stock pump pulls through the off electrics w/o problems. Detroit 2 cycles don't need bleeding - no injector pump.
I plan on adding them to my generators, Onan and Perkins, to make bleeding easier. Maybe replace the stock pump. The first 2 I paid about $50 each, but the price dropped to about $20 on ebay a couple years later. Competition, maybe?
 

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When I repowered w a Klassen engine (Mitsubishi) there was only the electric pump. I don't know if Mitsu shipped the engine from Japan w or w/o the lift pump but it appears that Klassen (now Yukon Engines) seems to think the electric is better.

I do also.
 
I kept the mechanical, but until I could get access to the starboard mechanical , I used a Carter electric, worked fine, till changed to original part. The original equipment work fine for 3400 hours. I do not like fixing what's working perfect for 3400 hours. Just changed out due to age.
 
When I repowered w a Klassen engine (Mitsubishi) there was only the electric pump. I don't know if Mitsu shipped the engine from Japan w or w/o the lift pump but it appears that Klassen (now Yukon Engines) seems to think the electric is better.

I do also.


The Vetus version of the Mitsubishi was also fitted with an electric pump.
(I just checked; the Mitsubishi S4L2 was originally built with an electric pump)

I love it. Fuel filter changes are much quicker, cleaner and simpler. The old filters can be pumped dry, then install new filters dry, then turn on pump for 10-20 seconds. Done.

They turn over a substantial amount of fuel. My electric pump circulates about 15 litres/hour while I normally use only 3 litres/hour, so about 80% is getting polished and sent back to the tank.

The only negative of having an electric lift pump, is that it may cover up a small leak in your fuel suction line, as the air would be bled out rather than stalling the engine. It's worth occasionally looking for wet spots on you fuel lines while shut down.
 
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I have electric pumps similar to the photo on each of my Detroit mains. Their rating is about the same as the mechanical gear pump. I only use them for filling my secondary filter, but leave them in place for emergency use. The stock pump pulls through the off electrics w/o problems. Detroit 2 cycles don't need bleeding - no injector pump.
I plan on adding them to my generators, Onan and Perkins, to make bleeding easier. Maybe replace the stock pump. The first 2 I paid about $50 each, but the price dropped to about $20 on ebay a couple years later. Competition, maybe?
I was wondering if the mechanical pump would have trouble pulling through an off electric pump... guess not.
 
You can pull through an electric plunger style pump, but not a rotary vane Carter style pump.

A reliable plunger pump is easy to install and uses little power.
I put one on my starboard gas engine. Advantage over rotary vane, the run a lot cooler, so the fuel is less likely to vapor lock which one warm day it did on me coming back into marina.

I got a Seachoice fuel pump = Facet fuel pump. Can pump 30 gph and lift 60 inches.
Seachoice name carries the USCG label, while the identical OEM facet name does not, other than the label these are the same pump. When I got mine, stamped into the metal foot tab is the Facet number 40288

Facet 40288
Seachoice 20341

Difference is Facet is less cost.
http://www.aircraftspruce.com/catalog/eppages/facetpumps.php
vs Seachoice
https://www.jmsonline.net/seachoice-cube-electronic-fuel-pump-kit-45-30psi-12v-scp-20341.htm/
 
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I was wondering if the mechanical pump would have trouble pulling through an off electric pump... guess not.

Before installing an electric, blow or suck air thru. You'll see on the pump type shown, there is almost zero restriction.
 
I have a Cummins 6BT on which I have installed a backup/polishing electric fuel pump, but I would never remove and plate off the mechanical pump. As long as it is fed clean fuel, it is likely to last many thousands of hours.
The R&D engineers down at Cummins have spent many hours and dollars to determine what is the best method to feed the beast, and I trust that to be worthy of due respect.
What do you figure the ratio of failed mechanical pumps would be in comparison to electrical failures?
 
I have a Cummins 6BT on which I have installed a backup/polishing electric fuel pump, but I would never remove and plate off the mechanical pump. As long as it is fed clean fuel, it is likely to last many thousands of hours.
The R&D engineers down at Cummins have spent many hours and dollars to determine what is the best method to feed the beast, and I trust that to be worthy of due respect.
What do you figure the ratio of failed mechanical pumps would be in comparison to electrical failures?

Since when did laymen, beat out engineers, who designed the Engine? I agree 100%, with you!
 
Bay Pelican has a Lehman 135. We are set up with the Walbro pump as a backup. Requires turning a valve to bypass the mechanical pump. Very useful when priming or in the situation we had where there was an air leak in the fuel supply lines. Allowed us to continue on.

Great addition as a backup.
 
I have known several folks who have had mechanical lift pump failures. Some replaced the mechanical and some just bypassed and used electric. All who have gone electric are happy but when my pump failed on my Perkins 4-236 I went went back with mechanical. The price wasn't too high. The old pump was still pumping but it was sending diesel into my crank case. Good thing I check my oil regularly. I was surprised to find my oil level rising! if this pump doesn't last long, I will switch to electric.

Kevin
 
Bay Pelican has a Lehman 135. We are set up with the Walbro pump as a backup. Requires turning a valve to bypass the mechanical pump. Very useful when priming or in the situation we had where there was an air leak in the fuel supply lines. Allowed us to continue on.

Great addition as a backup.

You win the award, for the most brains, on this issue, in my opinion.
 
Since when did laymen, beat out engineers, who designed the Engine? I agree 100%, with you!

By design I agree (I am a mechanical/design engineer).

However....I ran a Dodge/Cummins pickup truck for many years. The only time it failed me was because of a mechanical lift pump failure.
To clarify it was a replacement pump that was only a few months old. The rubber diaphragm inside the pump that acts as a "check valve" got eaten away by the fuel and became oval rather than round and would no longer make a seal when required.
So, doo doo happens.
 
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