Raw water pump

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Flyer
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Raw water pump

Post by Flyer »

I have recently purchased a PDQ with 100 hp Yanmars. I attempted to pull an impeller in order to be sure of having a spare on board. What a job! I have read some of the comments posted to this forum in the past which confirm the difficulty of accessing the pump. I know there are other options to using this gear-driven pump, like an electric pump. Have any forum members chosen an alternative to the factory pump?

Mike Anderson
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duetto
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Re: Raw water pump

Post by duetto »

hi,

on the main engines i would recommend sticking with the standard pumps. i wrote an article for last year's rendezvous on things to help doing an impeller change. the new yanmar oem impellers have threaded hubs which, when used with the yanmar puller, make getting the old impeller out easier. i've built a pvc compresser which makes getting it back in easier.

i also have a generator with an electric pump so i can talk about that option if you choose that route.
john & diane cummings
duetto mv34 #23
deising
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Re: Raw water pump

Post by deising »

I had an opportunity to view a new JH3 engine sitting on a rolling dolly not long. It is amazing how easy they are to work on when they are not closely surrounded by boat structure!

Due to a failure of the end of the camshaft driving the raw water pump on my sailboat engine years ago, I had to jury-rig an electric pump of the proper capacity to move the raw water for 6 weeks while traveling up the east coast until I could get a proper repair made. It worked fine, but I had to be sure to turn off the pump when I stopped the engine to avoid the water backing up into the exhaust ports.

There are lots of reasons to stay with the gear-driven raw water pump, despite the maintenance hassle. I used to do all my own maintenance, but with the extremely difficult access around these engines, I have had to pay mechanics at times who were more practiced contortionists and had better tools for reaching unwieldy places. I suspect the fuel I have saved from the efficiency of the narrow hulls has been more than offset by mechanics' fees.

Not a complaint; just an observation.
Duane Ising
m/v Diva Di
Punta Gorda, FL
2006 PDQ MV 34 - hull 91, 75HP, 3-blade
duetto
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Re: Raw water pump

Post by duetto »

duane points out probably the most important point when switching to an electric water pump, whether for generator or main engine. electric connection needs to be taken from a source which only gets power once the engine starts. the output stud on the alternator sounds like a good candidate.
john & diane cummings
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Re: Raw water pump

Post by wrnole »

John, sending you a PM.
Thanks,
Richard
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