Raw water pump

Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
This is my first go-round with the raw water pump leaking out the back. I follow the threads about them, and now I need to either replace or rebuild my B323 3YM20 pump- a Johnson. Are the bearings a machine-pressed fit, or are they are push-in or "hammer/dowel assisted"? I already started using some PB Blaster to soak into the nuts/bolts. Other than the usual Yanmar suppliers, has anyone come across a lesser-cost supplier?

While I'm on the stump, I thought I saved a thread about a solid-frame overhead bimini window. I searched for "bimini window" but the 4 results are not the one. Help?
 
Sep 15, 2009
6,244
S2 9.2a Fairhope Al
you can use a wood mallet and a 12 inch crescent/adjustable wrench to disassemble it....and the same mallet and a wrench and dowel to reassemble it i just redid one for my dock neighbor friday ...just make sure you don't remount it upside down because it will not pump ....oh and you will need some snap ring pliers...as for parts do a web search and get the best price you can
 
Jun 8, 2004
3,010
Catalina 320 Dana Point
I just bought a new pump for my 3GM30F, about $500, a Johnson pump comes without the bracket and pulley, same pump with a Yanmar number comes with bracket and pulley attached, about a $150 difference I think. My local supplier only carried the Yanmar's so was not much choice. Yanmar seems to change part numbers on an almost daily basis, even with the Johnson part number it took 30 minutes to track down the exact right one. The yanmar number had been changed several times and even some Johnson numbers had been changed. There are various Johnson pumps made using the same body but with different outputs due to the cam inside, two indentical pumps but one is 3 GPH and other is 5GPH at idle. While researching I did happen across a pump rebuilder in Oregon.
http://water-pump-rebuilders.com/yanmar-water-pumps.html
Your engine is the new version of mine and they use the same model Johnson pump which is an F4b-903 I believe.
They seem to run from about $300 to $700 new depending on exactly which one it is, I was just happy mine wasn't the $700 version.
 
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
A few years ago, I bought a Johnson raw water pump for my 1986 Yanmar 2GM20f from Depco for about half the price Yanmar wanted for it. Perfect fit and function. Thumbs up for Depco.
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
Just helped a friend rebuild his 2GM20 and he got the complete
rebuild kit from Yanmar dealer here in Ft Myers for $120.00 and all parts even cover and impeller except shaft and suppose to be same as 3GM30 pump.
My 3YM30 pump is not the same as the older 3GM30 pump
and was told all newer YM pumps are different than pumps
the older GM pumps.
 
Oct 29, 2005
2,366
Hunter Marine 326 303 Singapore
Ron,
Servicing the raw water pump is very easy and can be done cheaply if you buy the oil seal and bearings from local car parts shop. As for the shaft, if it need replacing, you have to get it from Yanmar dealer. When you got it serviced and installed back, don't tension the belt too much else it'll put pressure on one side of shaft and can cause leaks in no time.

Seadaddler,
BTW my 2GM20F pump is exact same as my friend's 3YM20 and 3YM30. My guess is ours are Europe spec engine. New pump probably has 19.5mm hose connection as oppose to 17mm for older ones.
 

RoyS

.
Jun 3, 2012
1,742
Hunter 33 Steamboat Wharf, Hull, MA
I would avoid pumpagents. They shipped me a wrong part needed to overhaul my pump. I spent about $150 for the parts and I was unable to correct this error by them. I repeatedly contacted them through their contact form but they never resolved the problem. At one time they sent me an email promising to send out the correct part "today" but that never happened. They do not list a telephone number. I contacted the original pump manufacturer and explained my problem. They looked at photographs of the plastic packages that the various parts came in and stated that they looked like extremely old stock. Further investigation on the internet revealed many similar complaints about this unresponsive company. Suggest avoiding them altogether.
 
Dec 19, 2006
5,832
Hunter 36 Punta Gorda
Ken
Last week when helping 2 friends one who had the 3GM30 and the one we rebuilt at the time showed their pumps were exactly the same pump was very different than my 3YM30.
I think you sent me the rebuild infomy 3YM30 ,the 2GM20 & 3GM30 had the 2 bearings next to each other with a clip in between and the pump has a half moon brass piece inside the pump housing and pump housing looks a little the same pump housing and the plate faces to the rear.
He paid $120 for the rebuild kit here in Fl and came with everything except shaft,new impeller,cover,all internal parts seals,bearings.
I thought that was a good deal for sure.
Not sure but yes your pump was the same as my 3YM30 but they older boats were different.
nick
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I bit the bullet since I am supposed to go to Wye Island this weekend and time is a factor. Paid 285 for a new pump, with brackets and tax. It took less time to change the pump -20 minutes- than just changing the belt itself. The biggest hassle was getting the old belt out and the new belt in since the gap between pulley and bracket is too narrow. AND, it does not leak! "As soon as the rush is over", I'll get into the old one to see if is rebuildable.
 
Sep 15, 2009
6,244
S2 9.2a Fairhope Al
BTW my 2GM20F pump is exact same as my friend's 3YM20 and 3YM30. My guess is ours are Europe spec engine. New pump probably has 19.5mm hose connection as oppose to 17mm for older ones.
the new pump also has reinforcing washers on each side if the pulley shaft and the older ones do not ...also the yanmar older ones have screw in hose barbs where the sherwood has permanent ones with a lip on the ends as opposed to just plane slick out sides