[C320-list] Impeller access on Yanmar 3GM30F engine

[Robert E. Sloat]

Ditto on taking off the pump to change the impeller on 3GM30Fs.  The pump is 
attached to a plate used to tension the dedicated water pump belt which is 
easy to unhook from the engine.  Then close the the thru hull at the sea 
water inlet and loosen the pump hose clamps.  I use a small container to 
catch the small amount of water that exits the hoses when you remove  the 
pump.  A good idea is to mark on the water pump its rotation direction when 
the engine is running so when you install the new impeller you turn the 
shaft in the correct direction.  You are looking at the impeller from the 
rear when working on the pump and things can get confusing unless you are 
sure of the pump's rotation.

My Yanmar tool kit that came with the boat has the wrenches that can do the 
pump removal and belt tensioning, but  I use my metric socket wrench and a 
small breaker bar or large screw driver to help readjust belt tension after 
the job is done.  The sockets are much easier to use than opened wrenches 
which if used by a novice can often leave tell tale evidence of rounded bolt 
heads.

Bob Sloat
Savannah Hull 894
----- Original Message ----- 
From: "Paul Adison" <pjaarch at verizon.net>
To: <C320-List at Catalina320.com>
Sent: Sunday, June 06, 2010 8:18 AM
Subject: Re: [C320-list] Impeller access on Yanmar 3GM30F engine


> Take off the pump. It's very easy. The job will take less than 10  minutes
>
> Sent from my iPhone
>
> On Jun 5, 2010, at 6:48 PM, argates2nd at comcast.net wrote:
>
>>
>>
>> When changing this impeller, do you take off the entire pump or  reach 
>> around the back of the pump to remove the 6 bolts?
>>
>>
>>
>> What tools except for a very short screwdriver?
>>
>>
>>
>> Rollie