Rebuilding Johnson Pump on Entec Generator?

[Dennis.G]

I have a 4 kW Entec generator on my sailboat. It's a Johnson dual unit pump (raw and coolant pumps on single shaft, engine driven). Have a bad bushing and very worn plates etc. Looking to replace or rebuild. Anyone have source advice for this pump unit? I have emailed SPX flow and Mastry Engine for help, but looking for any first hand advice on this.
Thanks

[svinshallah]

I worked on one of these years ago and found it frustratingly difficult. The owner finally decided to get a good electric pump for the raw water and just put a plate on the back of the fresh water pump. It was simple, cost effective, made impeller maintenance a snap.

[Dennis.G]

Originally Posted by svinshallah

I worked on one of these years ago and found it frustratingly difficult. The owner finally decided to get a good electric pump for the raw water and just put a plate on the back of the fresh water pump. It was simple, cost effective, made impeller maintenance a snap.

This may be a good idea. The pump failure all has to do with the second pump stacked onto the first. An electric pump would be a way to avoid that. I got part numbers for a replacement dual pump, and depending how expensive that is will decide between options.

[Al Dente]

I have this generator and have just made the conversion. My access was limited, changing the seawater impeller was difficult.....changing the coolant impeller just about impossible.
The new 12V pump circulates the coolant, the impeller pump the seawater. I also installed a Speedseal Life conversion to improve impeller life (http://www.speedseal.com/SpeedsealLi...dsealLife.html)
I managed to fit the electric pump under the motor on a plate next to the heat exchanger.



Sent from my iPad using Cruisers Sailing Forum

[Lepke]

Depco rebuilds most pumps and sells pump parts.

[ericoh88]

Originally Posted by Dennis.G

I have a 4 kW Entec generator on my sailboat. It's a Johnson dual unit pump (raw and coolant pumps on single shaft, engine driven). Have a bad bushing and very worn plates etc. Looking to replace or rebuild. Anyone have source advice for this pump unit? I have emailed SPX flow and Mastry Engine for help, but looking for any first hand advice on this.
Thanks

IMHO and FWIW

You can contact Doug Jensen <djense(at)mastry.com> He is very helpful and a quick call +13868721473 is faster to get the answer you are looking for.

The Johnson pump is the weakest link. You have 3 options.

1. Rebuild the pump and continue with the future risk of this pump failing which will allow the salt water into the FW side. This will corrode your thermostat - this is what happened to mine.

2. Remove the raw water and use a AC 110v March magnetic pump which is what I did. Caution - If you choose this route, this pump MUST be installed much lower than water line at all angle of heeling.

BC-3CP-MD 115 VOLT PUMP Each 342.00

3. Use a Johnson 12v pump for the fresh water side - a better option. I found out after buying the March pump .

10-24503-03 PUMP CM30P7-1 12V 1.00 Each 269.00

Entec came with the boat in 2013 - has some 1,100 hours. I added another 200 hours. Rebuild the whole unit. Replaced the fuel solenoid, valve springs, valves and the thermostat and bought the 110v March pump. I think the 12v path is better, well at least according to mastry's new machine design.

http://www.mastry.com/page.asp?p_key...16D5248827857D

For the initial trouble shooting when I could not get the entec to run according to specs, I had custom injector made for the compression test.

This little entec needs regular tightening of the valves and all the nuts. The fuel solenoid is finicky due to the high vibration.

Once caution is the fresh water tank does not have a breather with a reservoir. So I avoid filling the water to the max and allow some room for expansion or it may create undue pressure and cause leaks in other areas.

After spending 2.5k (for lots of spare parts on entec and a new March water pump etc) I came across a Northern Light look alike - a used Kohler 3 cyclinder with 51 hours only. Could not resist the price and paid for the genset in Feb 2015. Just took delivery in Jan 2016 and installed the kohler genset in the boat below floor board forward of the main engine.

Since I liveaboard and on the move with no space/house to keep the good old entec, I have since stripped the entec for parts ie the head block, injector, valve, valve spring, hx, parts for the pump and the custom injector fitting for compression test. Will sell them later when I have the time.

Let me know if you need more information on the performance of this unit. My only grip with this machine is I think the 4.2kw rating is a little too optimistic. When the unit gets heated up, the actual output drops - pretty much expected from a single cylinder with a large flywheel. I use it to run the AC so that means running this unit more than an hour - which is not good.

I like all the safety shut down features and yes do keep a few spare of capacitors.

The best feature of this little genset is the size and its simplicity.

[RaymondR]

I am finding this thread very helpful.


I am in the process of converting my Kubuto V2203 from raw water cooling to keel cooled and was considering converting the single impeller, shaft driven Johnston cooling water pump to dual impeller. This would allow me to leave the on-engine components of the existing system undisturbed (It is all hard piped and hose free and I would like to keep it that way) From what I have read in this thread, this option just dropped down the list of desirable solutions.


A second option was to install a second, smaller belt driven Johnston impeller pump however this is not too attractive due to the belt drive required and the shocking cost of even the smallest pumps.


The third option was a 12V Johnston pump connected through the ignition switch in series with an oil pressure switch so that the pump does not back flood the engine if the ignition switch is left on. I was not that keen on this one as whilst the electric pumps are much cheaper than the belt or shaft driven I was concerned with longevity issues.


The thread has been helpful in that it has decided me to go with the 12V electric option for which I can carry a complete spare pump for about the same cost as the belt driven option but a much simpler installation.

[ericoh88]

Originally Posted by RaymondR

I am finding this thread very helpful.

The thread has been helpful in that it has decided me to go with the 12V electric option for which I can carry a complete spare pump for about the same cost as the belt driven option but a much simpler installation.

RaymondR,

If your Kubota V2203 is http://www.kubotaengine.com/assets/d..._v2203m_28.pdf
looks like this is your main engine with 48hp @ 2,800 rpm, do you feel confident to rely on a small pump 12v for a critical operation?

Your Kubota is 2.16 liter displacement vs Entec Farymann 0.29 liter.

IMHO I would go for 2 Johnson pump because the flow using 2 impeller pumps driven by the engine belt will be more powerful than the 12v pump for this engine. I would replace the seals and impeller on an annual basis / religiously. What is the size of your impeller?

In the entec faryman case, I think the seals are broken by the fresh water side when the build up pressure were caused by the overfilling of the fw tank which does not has a pressure release valve to a reservoir tank.

Once the seals were broken, raw water could flow through the seal to the fresh water side.

[Finistere]

I bought the 110 volt raw water pump conversion from Entec a number of years ago, could not be happier. The pump starts pumping when the generator generates the voltage and therefore you cannot flood the engine with raw water by over cranking.




Sent from my iPad using Cruisers Sailing Forum

[Finistere]

I used to blow capacitors frequently until Entec advised to relocate the capacitor outside the sound shield, now they last for years.


Sent from my iPad using Cruisers Sailing Forum

[RaymondR]

The electric pump I am thinking of putting on the V2203 is just to supply raw water into the wet exhaust. The large shaft driven pump now used to supply raw water to the engine cooling system will now be used to circulate coolant through the engine and keel cooling tubes.


The electric impeller pump I am going to use for wet exhaust flooding has the same impeller as my small outboard which is convenient from a spares viewpoint.

[lowergard]

anyone have the actual part # to share for the Johnson dual pump on the entec generator?

[coreyevan]

I have and Entec West 4200 that I'm looking to sell, along with the 12 V water pump. I'm not up for the install and looking for another option. Message if interested.

[GordMay]

Greetings and welcome aboard the CF, Coreyevan.