30 Pilot II Yanmar seawater pump

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rgano

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Oct 8, 2007
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FROLIC
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Mainship 30 Pilot II since 2015. GB-42 1986-2015. Former Unlimited Tonnage Master
The lack of access for most maintenance actions on my 315 HP 6LPA-STP engine is atrociously lacking and nowhere more so than when dealing with the ridiculously placed seawater pump which must be removed to replace its impeller. Not only must it be removed, it must also have its impeller cover plate removed FIRST or it will jam up between the two engine studs which hold it in place an the engine mount behind the pump. Likewise, reinstalling the pump is a nightmare in which you have one hand with which to attempt getting the cover plate screws in while lying prone on cushions placed atop the engine.

I am solving a lot of this problem by removing the studs and using inch-long bolts in their stead.
 
RGANO,
I feel your pain. While I was winterizing the motor in November I notice a drip at the pump seal. I wound up deciding to pull the pump. Everything on my boat needs to be completed with one hand. It takes 2 hours to do a 15 min job. I wound up removing the top stud totally in order to remove the entire pump. I rebuilt the pump and when I went to put it back on I noticed I had slightly dented the lip on the face of the sealing surface at the o-ring. I broke down and bought a entire new pump and reinstalled. I saved the rebuilt one for a spare. What a pain in the ASS.
Jeff.
 
Such is life when you take an automotive engine and try to fit a sea water pump to it someplace. It is a PITA to remove the pump on even my Yanmar 6LY which I think was designed from the ground up as a marine engine. The 6BTA Cummins isn't much better. I think you have to jack up the engine an inch or so to get the pump out and clear the motor mounts.

At least I can crawl down beside the engine on my boat and use two hands. I shudder to think about doing this job on a twin though. The joys of maintaining a marine engine yourself!

David
 
Just replaced the impeller on my 34 pilot. Had plenty of room to perform work. A single motor is the way to go.
I had a 30 ' pilot with a single motor and change the pump by crawling through the access hole at interior stairs. Tight fit but doable.
Good luck
 
The lack of access for most maintenance actions on my 315 HP 6LPA-STP engine is atrociously lacking and nowhere more so than when dealing with the ridiculously placed seawater pump which must be removed to replace its impeller. Not only must it be removed, it must also have its impeller cover plate removed FIRST or it will jam up between the two engine studs which hold it in place an the engine mount behind the pump. Likewise, reinstalling the pump is a nightmare in which you have one hand with which to attempt getting the cover plate screws in while lying prone on cushions placed atop the engine.

I am solving a lot of this problem by removing the studs and using inch-long bolts in their stead.
I just bought a "new to me" mainship pilot 30 II with the 315hp yanmar and need to replace the impeller also. Can you tell me what is the orientation of the bolts holding the pump to the motor? Are the bolts parallel to or perpendiculat to the crankshaft. Can I remove them with a socket while lying atop the engine? I am referring to the sea water pump removal.
 
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I just bought a "new to me" mainship pilot 30 II with the 315hp yanmar and need to replace the impeller also. Can you tell me what is the orientation of the bolts holding the pump to the motor? Are the bolts parallel to or perpendiculat to the crankshaft. Can I remove them with a socket while lying atop the engine? I am referring to the sea water pump removal.

George, you are we wlcome to write me direct at richgano@gmail.com about any topic regarding the Pilot 30. I have had mine since June 2015 and have completed quite a list of improvements and alterations to make the boat more reliable and a bit easier to work on.

Regarding the seawater pump, the two 14 mm NUTS holding the pump onto the studs are oriented parallel to the crank. And cannot be removed with anything but an open end wrench. HOWEVER, you must remove the impeller cover plate FIRST because the darned thing is JUUUST thick enough (at last on my engine) to prevent the pump's clearing the ends of those two studs as you got to pull it clear. To make things simpler, remove those two studs so that you can attach the pump to the engine with more easily managed bolts.
 
George, you are we wlcome to write me direct at richgano@gmail.com about any topic regarding the Pilot 30. I have had mine since June 2015 and have completed quite a list of improvements and alterations to make the boat more reliable and a bit easier to work on.

Regarding the seawater pump, the two 14 mm NUTS holding the pump onto the studs are oriented parallel to the crank. And cannot be removed with anything but an open end wrench. HOWEVER, you must remove the impeller cover plate FIRST because the darned thing is JUUUST thick enough (at last on my engine) to prevent the pump's clearing the ends of those two studs as you got to pull it clear. To make things simpler, remove those two studs so that you can attach the pump to the engine with more easily managed bolts.

Thank you Rich for that. I have the cover plate off. Sounds like I still need to crawl down along side the engine to get at the nuts. Does that sound right?
 
I lay a couple of throwable cushions top the engine and lie down on top of them while reaching down the port side of the engine to the area of the pump with my left hand. No way Am I going to fit tryng to crawl in from the opening under the cabin ladder. It helps that I am left-handed. :)
 
I lay a couple of throwable cushions top the engine and lie down on top of them while reaching down the port side of the engine to the area of the pump with my left hand. No way Am I going to fit tryng to crawl in from the opening under the cabin ladder. It helps that I am left-handed. :)

So it can be done from atop the engine. I can only get my head into the forward engine access, and maybe one arm also. My son is coming to help and he is small, but strong and flexible and can easily get alongside the engine from the back end of the engine. At my old age and lumbar fusion surgery just 2 years ago, I am inflexible. I followed one of the Forum's members suggestions and made an impeller compresser with plastic and hose clamp so it should be a little easier.
 
Using the tools available (i.e. a smaller flexible person) is a great idea. However, even though I was able to get the cover plate off the pump while working from above, I was unable to get the old impeller out which is why I had to remove the entire pump (and in the process also changed out the studs in favor of bolts). Due to dual Racor filters, the large seawater strainer, and the Floscan installation on the port side of my engine, not even your son could get alongside my engine.
 
Using the tools available (i.e. a smaller flexible person) is a great idea. However, even though I was able to get the cover plate off the pump while working from above, I was unable to get the old impeller out which is why I had to remove the entire pump (and in the process also changed out the studs in favor of bolts). Due to dual Racor filters, the large seawater strainer, and the Floscan installation on the port side of my engine, not even your son could get alongside my engine.

I see your problem. I only have a single Racor, no Floscan. I do have the large strainer which is not in the way to crawl forward on port side. I'm thinking maybe we both need a Pilot 34 footer with a single 315hp.:socool::socool:
 
I think if I had a 34, I'd want a bigger engine like maybe a 370 in order to get the speed I am used to. Hopefully, access would still be good!
 
I think if I had a 34, I'd want a bigger engine like maybe a 370 in order to get the speed I am used to. Hopefully, access would still be good!

The new impeller job is now done and water is pumping like a fire hose. My son was able to easily crawl alongside and put in the new impeller, attach the cover and clean out the forward hose of bits of vanes. The other hose was clean earlier when we removed the end caps on the heat exchanger and rodded-out the tube bundles.
All good finally. Thanks.
:):)
 
Thank goodness for skinny sons!! Working one-handed from above, I was unable to gt the impeller out or in and thus had to pull the whole pump.
 

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