Electric fuel pump to replace lift pump Yanmar 3GM30F
- Thread starter skunther
- Start date
My 4JH4AE came with a fuel pump. The actual Yanmar pumps are quite expensive, of course...
I have looked on Amazon, but stayed with the official product out of paranoia.
Anyway - if it is of any help, the one my engine has looks like this, and there are many less expensive lookalikes on Amazon as well.
I have looked on Amazon, but stayed with the official product out of paranoia.
Anyway - if it is of any help, the one my engine has looks like this, and there are many less expensive lookalikes on Amazon as well.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,786
Many years ago I had problems with the factory installed lift pump on my 2GM20F and decided to go with an electric pump.
After doing the homework on everything I could find about electric pumps, this is what I came up with :
The reason for choosing this pump is that it would still pass fuel even if the pump failed :
Running the engine at full throttle (3600 RPM), the electrical contact was removed from the pump and only a very slight drop in RPM was noticed. Few pumps mention if this option is available :
The pump was installed after the primary filter to ensure a clean supply of fuel to the pump :
It's been in service for about 12 years without any problems.
After doing the homework on everything I could find about electric pumps, this is what I came up with :
The reason for choosing this pump is that it would still pass fuel even if the pump failed :
Running the engine at full throttle (3600 RPM), the electrical contact was removed from the pump and only a very slight drop in RPM was noticed. Few pumps mention if this option is available :
The pump was installed after the primary filter to ensure a clean supply of fuel to the pump :
It's been in service for about 12 years without any problems.
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Why bypass the lift pump??? The fuel system is so simple on these engines.... it requires very little maintenance, why add something electrical that creates a new "something" to fail? If the lift pump is leaking / rusted, replace it? It will serve you many many many years .....
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There are probably a few reasons that somebody may want to do this.
#1 mechanical lift pump is no longer working and out-of-scope dollars and time to replace it.
#2. Having a properly specced electric pump in advance reduces overall pressures on the mechanical fuel pump and increases life time.
#3. People are lazy. The easier you make it for them to do basic maintenance tasks such as replacing fuel filters means they will do it more often.
#3A (corollary):Clean fuel reduces problems.
Good stuff RJ, as usual. I’m curious why you have a loop in your fuel line either side of the Racor.
Do you (or does anyone) know the psi of the stock lift pump? I’ve read 2-4psi. I’ve also read 4-6psi. The pump I referenced in the OP is 1.5-3, while RJ’s is 3-4.5. I don’t know how much this difference matters, and am inclined to go with the cube he referenced as it can be installed in any orientation, while the posi-Flo I linked likes a horizontal position.
Still, adding an electrical device to a mechanical engine is increasing complexity and modes of failure....
As for purging air after a filter change. If you do one filter, run the engine, then the other filter, very little priming is necessary. If both filters are done at the same time, then get ready to flick that little lever 100 times !
To each their own .... my experience when taking on a used boat and putting it into a rental fleet is that bringing things back to stock is usually better in terms of reliability. Sometimes "improvements"(aka owner mods) just mask other issues. .... .your mileage may vary!
As for purging air after a filter change. If you do one filter, run the engine, then the other filter, very little priming is necessary. If both filters are done at the same time, then get ready to flick that little lever 100 times !
To each their own .... my experience when taking on a used boat and putting it into a rental fleet is that bringing things back to stock is usually better in terms of reliability. Sometimes "improvements"(aka owner mods) just mask other issues. .... .your mileage may vary!
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Your choice doesn't come close to the pump specs used on Westerbeke Universal engines - Facet 476459N. These pumps have a mil-spec # and meet Coast Guard specs. They are bullet proof and will last for decades if you clean the filter every few years. The bottom twists off for access. Mine was still running after 30 years. A mechanic told me whenever he sees one in the trash he takes it out, cleans the filter and reuses it. They are available on Amazon but are available for $20 less from car racing sites.
The pump that Ralph came up with specifies "Not for use with fuel injected engines".
The pump that Ralph came up with specifies "Not for use with fuel injected engines".
Thanks @Jan11 , I will look into that pump.
@marcham, thanks for your input. I have researched this to my satisfaction and already made my decision to go with an electric pump. I did not start this thread looking to debate the merits of electric versus mechanical, as there are many threads on this already. I am inquiring as to the most appropriate electric pump.
@marcham, thanks for your input. I have researched this to my satisfaction and already made my decision to go with an electric pump. I did not start this thread looking to debate the merits of electric versus mechanical, as there are many threads on this already. I am inquiring as to the most appropriate electric pump.
The Racor 110A fuel filter requies a few inches below it to remove the filter element. The factory installation located it within a run of tubing and electrical wires. A monumental undertaking trying to protect this mess while replacing the filter core :
The only way to avoid this was to move the filter further aft. This meant the filter would now sit 1/2" off the hull bottom. The filter was now installed so that it was removable from its mounting and it could be worked on in one's lap while all hoses remained attached :
Lift pump output pressure is :
1.4224 PSI which is just enough to ensure the high pressure pump always always has a positive pump suction.
I was forced to go with a higher pressure for my electric pump but was assured by my Yanmar dealer that any pressure would be fine. The purpose of the lift pump is to ensure that the high pressure pump is not crunching down on any vapour bubbles which would make for erratic running. My findings showed no problems at the higher suction pressure for the high pressure pump. Way back when, this was all that was available in the little CUBE electronic fuel pumps.
Yeah, I hear you. Same warning way back when as today.
My Yanmar dealer had no explanation as to why the CUBE pump would not be suitable for a fuel injected engine (diesel). Maybe the warning was intended for gasoline fuel injected engines. My engine is content at 3,600 RPM WOT which is all I asked for. Normal cruising is at 80% of WOT ≈ 2,900 RPM.
There are far more pumps available today as opposed to 20 years ago and there are a vast array of pumps which will do the required job of supplying a small pleasure craft diesel engine.
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