[C320-list] Changing the Impeller

[JJ Morrison]

Isn't it interesting; my 3GM30F has an impeller with a keyway in it instead of a screw fitting into a slotted shaft?? I change it as per the below and certainly don't recommend trying it with the pump attached to the engine. I know there is a kit available with thumb screws for the plate which would probably allow replacement on the engine.
Cheers
JohnM
1999#574
 

> From: resloat at comcast.net
> To: C320-List at Catalina320.com
> Date: Wed, 27 Jul 2011 09:04:48 -0500
> Subject: Re: [C320-list] Changing the Impeller
> 
> I do what Paul does on my 3GM30F Yanmar. It is a lot easier to remove the 
> pump than to try to get off the backing plate with the pump mounted on the 
> motor.
> 
> Just close the thru hull for the sea water pump, loosen the pump from the 
> engine, take off the hoses from the pump one at a time and drain any water 
> into a small can. (I keep a dry bilge.) With the pump on a towel in a 
> convenient location carefully and remove the backing plate. The screws are 
> slotted so use a screw driver with the widest blade that fits the screws to 
> prevent stripping them. When the plate is off, you then grab the screw in 
> the hub of the impeller with a long nose pliers and pull out the impeller. 
> You may need to nudge the impeller a little to get it out. I mark the pump 
> on the painted side to show pulley rotation direction and mark the plate so 
> it is put back in the same position as when taken off.
> 
> Put some glycerin, soap or other water soluble lubricant inside the pump and 
> on the impeller and any O rings that seal the plate and install the 
> impeller. I gently rotate the pulley in the direction shown by your 
> markings before putting on the plate just to make sure the vanes look fine. 
> Starting the engine does the same, but it is an instantaneous 900 rpm. 
> Install the plate, the pump, the pulley, then the hoses and tension to spec. 
> Make sure the pulley is in the slot on the crankshaft pulley and then 
> tension.
> 
> Open the thru hull, start up the engine and check for water coming out of 
> the exhaust and for leaks at the sea pump.
> 
> I remove the impeller when on the tarmac for winter storage and install it 
> prior to launch and the drill takes less than 15 minutes.
> 
> I believe the Yanmar tool kit has all the metric open-ended wrenches for 
> this job, but I use the metric sockets from my on-board tool box. You can 
> tension the pump belt by prying with a long wrench or bar as long a you are 
> careful not to scratch or burr the pulley. If you are not confident in doing 
> this put a wooden block or a heavy folded towel where the pry bar meets the 
> pulley.
> 
> The drawings on the instruction sheets that come with the impeller sometimes 
> show the impeller rotation in the opposite direction from the 3GM30F which 
> can cause confusion, so I just install the impeller and turn the pulley 
> according to my markings on the pump.
> 
> Bob Sloat
> Savannah 894
> ----- Original Message ----- 
> From: "Paul Rickman" <ilove2sail at verizon.net>
> To: <C320-List at Catalina320.com>
> Sent: Tuesday, July 26, 2011 11:50 AM
> Subject: Re: [C320-list] Changing the Impeller, Changing the Oil
> 
> 
> I take the hoses off and work on the water pump away from the motor.
> Very easy to do and no problem to tension the belts.
> 
> Changing the oil with that TOPSIDERS is a snap, your approach is
> correct.
> 
> Paul
> Affinity 657
> Bay Bridge Marina
> Chesapeake Bay, Maryland
> 
> 
> 
> 
> 
> ________________________________
> From: Jason Alexander <alexander.jason at gmail.com>
> To: c320-list <C320-List at catalina320.com>
> Sent: Tue, July 26, 2011 12:40:08 PM
> Subject: [C320-list] Changing the Impeller, Changing the Oil
> 
> Hello,
> 
> I have the Euro 3GM30F Yammar in my 320. I was looking at the water
> pump last weekend to get the necessary info to order a new impeller
> and noticed that the cover plate faces the engine and would appear to
> make it very difficult to change the impeller.
> 
> What do people do to get a new impeller installed. Do you remove the
> pump from the engine? If so is it hard to get the belt tensioned
> again?
> 
> 
> As for the oil change I have a topsiders oil extractor. Do you just
> go down through the dip stick to extract the oil. On the Catalina 28
> I had a while ago there was a nice drain hose connected to a fitting
> on the bottom of the oil pan. Made changing the oil very simple.
> 
> Thanks,
> Jason
> 
>