SailNet Community - Reply to Topic
Thread: Water Pump Yanmar 2GM20F Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

  Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below

  Topic Review (Newest First)
02-27-2008 09:16 AM
Originally Posted by puff6022 View Post
Island Packet says there is no way the thruhull comes out of the water on either tack
Call Island Packet and tell them you found a way .
02-27-2008 08:19 AM
puff6022 I found the problem, On a strong starboard tack (my thru hull is on the starboard side) the thru hull comes out of the water allowing the hole system to drain and loose prime. I am going to install a check valve between the thru hull seacock and my raw water strainer. I've had the boat since 2001 and never had the problem until now. I just replaced my sails, and therefore heel more. Thanks for all the input.
02-23-2008 09:43 PM
mmorio sorry forgot to mention, same engine 2gm20 on a hunter 30
02-23-2008 09:38 PM
Similar problem - no Water at all - is there really a way to prime?

Hi all,

I just got my boat back in the water after a broken prop and bent shaft (long story but it has to do with a submerged deadhead and on the way OUT on a 4 day weekend. grrr...)

When I started the motor up I had no water move through the system at all. Last year I replaced my mixing elbow which was the culprit but I can't imagine it built up soot and blocked again so quickly.

The boat has been in the yard for work (and waiting for parts) for about 45 days and I could not find any blockage when I checked the sea ****, strainer and impeller this afternoon and all seemed to have water. Any ideas what may be the problem? When the yard replaced the prop shaft, does that have any effect on the cooling system? Is there an easy way to check the heat exchanger? Could it be something simple I just didn't see? Yes, I opened the throughull

I noticed a couple posts about the pump "priming" how would I bleed air out of the system to prime it?

thanks in advance!
02-22-2008 03:12 AM
trantor12020 Could your impeller be fitted in wrong direction? I know the 2GM20F water pump (Johnson 810) doesn't follow the direction indicated on the pump cover plate. Mine is reverse.
02-22-2008 02:12 AM
badsanta If your fresh water pump vains were damaged before rebuild you may have rubber pieces blocking the heat exchanger tubes.
How do you know you are lousing prime? If you are saying no water comes out the exaust when the motor is running, Then either the thru hull intake valve is closed, or the fresh water pump is bad or the power belt is loose or broke or the heat exchanger is clogged. Or your exaust elbow is cloged.
I would look at the heatexchanger and the exaust elbow. Unless you have other info
02-13-2008 09:02 PM
blt2ski I got a leak in my 85 2gm20f about Jan 1. the gasket went haywire. I did not have a gasket so found and made do with some gasket material. was too big, so no fluid would pump thru. Removed the gasket all together, and used some Tstat silicone tween the back and the main unit, and it works fine now. Unfortuneatly, had a small over heat issue last sunday in some 30-40 knot winds!

Otherwise, I am not sure what to say re losing the prime. As i was checking initially to see why no water would go thru. One of my tests, was to open the valve with the pump not connected, and water would flow up thru my hose. Next step was to see if any got to the inlet in the radiator part. Nothing. So that left the pump for me anyway, not working at all.

Not sure why, other than maybe something is floating around in the inlet that you can not see, ie a rock, small sea shell type creature etc

02-13-2008 11:45 AM
JohnRPollard Some discussion of problematic prime here:

EDIT: Another thread:
02-13-2008 11:27 AM
RickBowman Your pump is self priming. What's the problem?
02-13-2008 10:36 AM
PBzeer If you don't lose your prime when sailing or motoring flat, and you do when heeled, something is stopping the inflow of water.
This thread has more than 10 replies. Click here to review the whole thread.

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

For the best viewing experience please update your browser to Google Chrome