Winterising Diesel Inboards

[MadFrank]

Rather than paying my boatyard to winterise my new boat - could anyone please give me some basic instructions.

My engine is a 9HP Yanmar Diesel inboard with seacock and external exhaust pipe with an anti-flowback chamber.

Thanks in advance

 

[ccscott49]

Once the boat is out of the water, flush the engine through, with a pipe stuck up the seawater inlet and the other end in a bucket, higher than the inlet, with a mixture of 25% antifreeze, 25% soluble oil and 50% water, start the engine and allow all this mixture to be run through the engine, when it's all gone, stop the engine, it will be easier with two of you. Is this engine fresh water cooled? If so check your antifreeze in the engine, you will need an antifreeze tester for this, or if it looks a bit weak, drain some water out and bung in about a litre or two, it doesn't matter if the mixture is too strong! Close the seacock, take out the impellor, and tie it to the keys, replace the cover loosely, which will drain the seawater side. Remove and top up the battery to take home or arrange for a trickmle charger. Spray everything on the engine with wd 40 or equivalent, Change the engine oil and filter, change/clean the air filter, lubricate any linkages, change/check the gearbox oil. (service the engine and box) If the boat is to stay in the water, do everything the same, but close the seacock, disconnect the pipe to it and put it in the bucket, after flushing recconect the hose to the seacock and tighten it up, leave it closed. Thats about it, Oh! put silicon grease on the battery terminals and the starter terminals. Can't think of anything else, hope this helps.

 

[tim]

I had the same query last year. I posted an email to the PBO technical help, to which they kindly replied and eventually printed in PBO.

 

[HappyHunter]

Wow! Maybe I should pay the boatyard after all!


My plan is to keep my boat in the water until Christmas at the earliest. Beyond dealing with the antifreeze, is there anything else that is vital. Engine has probably run no more than 50 hours in the year since the last professional overhaul, and I'm a bit reluctant to start changing everything unnecessarily. Is this penny wise pound foolish?

 

[dickhicks]

Do just as colin says, the only difference is change the engine oil FIRST whilst still afloat and run it for a few minutes to circulate the new oil. Oh, and stuff a rag up the exhaust pipe.

 

[HaraldS]

Great list! The only additional thing coming to my mind is to slacken the V-belts.

 

[andy_wilson]

1. Ask boatyard for detailed spec. of their work, plus pricing before you commit to book.

2. Out of courtesy ring them to say you have changed your mind about the work and you are just going to hope for the best instead.

3. Run the engine long and hard before draining the old stuff and changing oil and filter.

4. Let them jet off the bottom when they lift her out.

5. Follow the remainder of their routine to the letter.

6. Carefully wash and dry the batteries and thoroughly charge every 4-6 weeks (or put on trickle all winter). If you leave them aboard, put the charger in with the engine for some gentle dry heat. If you take them home, do not store on a porous surface (eg concrete garage floor). Salty deposits left on battery tops, damp porous surfaces, and natural self discharge will conspire to flatten a battery in a few weeks.

 

[dickh]

Volvo Penta do a DIY booklet which comprehensively describes all you have to do - very useful and although you have a yanmar, the principles are the same. Don't know how much it costs though...

dickh
I'd rather be sailing...

 

[vyv_cox]

Colin's list is fine and includes virtually everything I would do. My only additional action concerns the water trap. Leaving water in there both attracts the possibility that it will freeze, dependent upon location of course, splitting the unit, but also that the saturated air will corrode the engine exhaust valves and possibly the bores. I always drain mine before putting some rag up the exhaust.

I wouldn't bother with the soluble oil as I can't see what benefits it has. With a raw water cooled engine I prefer to circulate the antifreeze solution a few times, drawing pump suction from the water discharged through the exhaust. However, most engines will survive for many years without any flushing.

I've come to the conclusion that re-using the impeller is a false economy. Two years ago a re-used one failed mid-season, leading to a difficult situation right in the entrance to Scheveningen harbour. We found later that the trap had almost melted right through during this incident, although the engine only ran water-free for under a minute.

 

[steffen]

To prevent water remaining in the various parts of the engine, including the exhaust, i run the engine until its warm thus opening the thermostat. Then i replace the water by pure anti-freeze coolant by putting the intake hose into the coolant container until the exhaust spits out the -usually colored- coolant.
Do put a bucket under the exhaust to prevent the coolant from getting into the environment.

 

[JerryHawkins]

Have a look at...

this web site:

http://boatdiesel.com/Maintenance/Laying_Up.cfm

has good info on other aspects of diesels too.

Cheers,

Jerry

 

[MadFrank]

Thanks for all the many replies - much appreciated.

The boat will be removed from the water completely and will be sitting on my drive ready for the ultra-pleasant yearly antifoul and paint scrubbing......