I purchased a 2002 Hunter 456 recently and spending the next few seasons getting to know her. This past winterizing experience has been a good education. I'm now stuck at the impeller. The raw water pump on my Yanmar 4JH3-TE is tucked behind and under the alternator and facing aft up against the port bulkhead in the engine compartment. Needless to say, I can't see it and can barely get my fingers on it. Does anyone else have this configuration, and how have you managed? Thanks, SS
Accessing / Replacing Raw Water Impeller
- Thread starter Semper Sailor
- Start date
Any chance you can supply a few pictures ?
Sounds like the sort of thing that makes one ill at first sight.
Sounds like the sort of thing that makes one ill at first sight.
I don't know the engine or boat, but do you think it might be easier to remove the whole pump, rather than trying to reach the impeller?
A bit different model boat here, but the sea water pump on our engine is in the same location. Replacing our impeller was pretty easy. Four machined screws hold the pump cover on. Wiggle the old impeller out with needle nose pliers, but remember the vane rotation. Clean the pump face of any old gasket material. Install the new one with the correct vane rotation using the lubricate supplied with the new impeller.
How many hours do you have on the engine/impeller? Does it really need replacing? Purchased our boat in 2002 with about 600 hours. Replaced that impeller last year with about 2,200 hours on the engine. The old impeller looked just like new, so will keep it as a spare.
How many hours do you have on the engine/impeller? Does it really need replacing? Purchased our boat in 2002 with about 600 hours. Replaced that impeller last year with about 2,200 hours on the engine. The old impeller looked just like new, so will keep it as a spare.
Same issue on my Hunter 386. Had to disconnect the transmission and front motor mount, jack the motor up and rotate the alternator to get access to it.
Same experience. Replaced old impeller at 1,000 hours because I had it apart for an inspection. Looked like new and saved as a spare.
I wrote up a modification. It’s posted on the site. After implementing this, you’ll be able to change your impeller in 10 minutes.
The Yanmar design was awful. I suggest you look into the mod
My engine has pretty low hours...~360. Hopefully, I'll find the impeller looking great, but I need to know...
I think you're right, Artboas. I'm going to have to "dig it out" and I might as well modify while I have the peripherals removed and disassembled...
You will not regret doing this.
Its literally a day’s work, and $300. And you’re done.
Try to imagine changing the impeller (as it exists), off the dock in a seaway. Simply not possible.
Pm me if you need help