Cruisers Forum

Thread Tools Search this Thread Rate Thread Display Modes
Old 09-04-2020, 09:19   #16
Registered User
Boatyarddog's Avatar

Join Date: Nov 2014
Location: Olympia, Wa
Boat: 1979 Mariner Ketch 32-Hull 202
Posts: 1,248
Images: 2
Re: Yanmar engine Seized in a sailboat

Originally Posted by openseas View Post
Hi all,

I have a sailboat with a Yanmar engine 2QM15 ( 1980 model, 15hp). The boat was on a dry dock for 12 years straight. When I used the boat last, the engine ran normal.

Yesterday, I changed the oil and filter, thermostat and water pump, fuel filter and drained old diesel.

I disconnected the hose that comes from the seacock to the water pump, and connected the water pump to a garden faucet through a hose, and tightened the hose with with a clamp. I opened the water, then started the engine, and it ran immediately. I let it run for 15 minutes, then I turned off the engine, then the water.

Today I tried to start the engine the same way. The engine turned half a round and locked. I turned off the water, then removed the air filter and box, since I found water coming out from that area, as I tried to crank the engine manually to the right and left slowly, the water was coming out of the air filter area in pulses as I was cranking it, repeated this few times, till no water came out, and the engine would crank again complete round.
I opened the garden hose again, but not all the way this time, and I started the engine, after few attempts, it ran like normal.
I let it run for 10 minutes and turned it off.
My question is:

- How the water can go inside the cylinder from the cooling system?
- Will the water stay there and cause later damage?
- Should I do anything further?
I don't know much about mechanic, and I need your help.

Thank you in Advance,

All good answers, next time, use a ball valve inline to inturrupt flow, regulate hose pressure at the engine.
Best use a bucket though, you can also winterize the raw water loop this way.
Just be sure to use the pink RV antifreeze full strength. (Propylene glycol based.)
Not regular car antifreeze. (Ethylene Glycol based)
SV Cloud Duster
SV Cloud Duster
Boatyarddog is offline   Reply With Quote
Old 10-04-2020, 06:45   #17
Registered User

Join Date: Apr 2017
Location: Hingham
Boat: Dickerson 37AC
Posts: 665
Re: Yanmar engine Seized in a sailboat

All good answers previously. I also do the bucket of water in the cockpit with hose filling the bucket. Have hose from water pump to suck out of this bucket.

A couple very important tips I have learned...

If the bucket is above the water pump (likely), it will continue to siphon and can cause the engine to keep sucking water until the siphon breaks. I found this out the hard way when winterizing with antifreeze. I shut the engine off, lifted the tube and the slug drained into the engine. Found out in the spring when my oil was milky. Fortunately I checked before I fired it up.

Now I run the bucket dry (either water or antifreeze), lift the hose up (engine still running) until I can clearly hear the water pump is now sucking air (10 secs approx). Only then will I shut down the engine and know I don't have a siphon.

2 years ago my uncle waterlocked his Yanmar doing something similar with the bucket and got lucky. Said when he was turning over by hand he could hear water in the cyl.

I ended up needing to change the oil 4-5 times to get rid of the antifreeze. Once boat went in the water, I ran it hard for an hour and then changed again. No issues.
sailah is offline   Reply With Quote

boat, engine, sail, sailboat, yanmar

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLD] YANMAR 4JH2E ENGINE (SEIZED) bretto55 Classifieds Archive 5 24-03-2015 21:22
Looking at boat with seized engine sanibel sailor Engines and Propulsion Systems 27 14-02-2015 11:50
Seized engine MD 30 Volvo penta Sergy Engines and Propulsion Systems 4 15-08-2013 06:16
Seized Engine Zinc sneuman Engines and Propulsion Systems 9 01-12-2011 11:37
Seized Engine hawkeyejsk Engines and Propulsion Systems 15 25-09-2009 23:33

Advertise Here

All times are GMT -7. The time now is 20:33.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.