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  Topic Review (Newest First)
07-17-2011 10:52 PM
Classic30 All good tips.. Thanks, guys!

Ilenart, I do keep all thru-hulls closed when not in use - more from routine than anything else - but it's interesting to hear having them open can add to electrolysis! Makes sense, but isn't not something I've heard before..
07-15-2011 09:53 PM
Over Analyzed

Here is my procedure:
  • Turn on motor as soon as I get to the boat
  • Idle motor until it warms up. My engine smooths out when it achieves "warm up"
  • While warming up. Raise main sail, get ready to cast off.
  • Engage transmission BWD/FWD to make sure tranny works.
  • Cast off and either motor sail or sail off with motor in neutral. If motor sailing, 2000 RPM min. Min motro time is 15 min.
  • Once comfortable with power under sail, turn off motor.

Typically, we motor for 10 -15 minutes, full load on, the return. Minimum rpm is 2400. Once back at mooring allow cool for 5 minutes. Every month I motor for 30 minutes at 2800 RPM with 1 min bursts at 3200 to 3600 RPM.

Motor, Yanmar 3GM30F,
07-15-2011 10:22 AM
blt2ski Idling is BAD for ANY motor, be it gas, diesel, propane etc. Many times the heat or should we say lack of will not warm up the motor. Bad combustion etc. Unless it is REALLY cold, ie below 0C/32F, I start the motor, and take off, be it my trucks, boat, bobcat/trackhoe etc. The latter two, I might full throttle idle a bit in colder weather, that is more to warm up the hydraulic fluid propulsion system more than anything. Then again, full throttle for those two is probably 3/4 throttle for a boat or vehicle.

Change filters regularly, add some biocide/antigel if the thing will sit for awhile, especially in lower temps, reality is, a diesel is easier to maintain than a gas rig. I just had to buy a new carb for a mower than had this 10% alcohol mix sh!t we have here in NA right now, destroyed the rubber with water collections in it. What a pain, time lost for working etc. Biodiesel is not too bad to work with either, but it does gel a bit sooner than straight diesel, so antigel will be needed in temps closer to 0C than straight diesel.


ps, no camaron, doggy fetch is not what is ment, altho close!
07-15-2011 09:21 AM
PCP well, I had a Volvo for 7 years, done 2400 hours with it and followed by the "book". Never had a problem and the engine was running like a new one (still is, wit a new owner).

When the boat was on the water and the weather was too disagreeable to go out, I operated the engine at least all 15 days. First let him run for 1m at idle, then forward at 1000 rpm for 3 or 4 minutes than increase to 1200/1300 for more 2 or 3 minutes, then put it in reverse at a 1000rpm for some minutes and at 1200/1300 for 3 or 4. I finished with some sharp acceleration with the boat in neutral (10 or 15s with the boat at 2400 rpm).

When the boat was out of water in the winter (only one winter) I have followed the Volvo instructions for that situation (or better I gave instructions for doing it since the boat was far away).


07-15-2011 07:10 AM
Ilenart Cameron,

I have heard that you do not want to run the engine under no or low load due to the build up of carbon, that someone has already mentioned, plus "glazing" the cylinders (whatever that means, however it does not sound to good). My manual (which I cannot find at the moment) talks about running the engine at least 70% for the majority of time. If I have to idle the engine for more than 60 minutes the manual saids to "race" the engine at 2,000 to 3,000 rpm every hour for at least 2-3 minutes.

So I think you are right in letting the engine idle for at least 5 minutes, then run under load. In winter I generally take Amadeus out for a run around once a month for around an hour and most of the time its around 80-100% of throttle. Good excuse to take the yacht out. If I am in a hurry I will run the engine at around 1,200rpm in the pen.

However, like other have said, if the motor sits still for a couple of months it's not going to be a big deal.

One tip I have worked out; make sure you close your thru hull for the sea water inlet when you leave the yacht. This will reduce the corrosion on the inside of the engine. A friend of mine with a steel yacht has a device that measures the amount of electrolysis current flowing into his yacht and the measurement goes up by a factor of 4 when his engine seawater thru hull is open, compared to when it is closed. Also good practice to close all thru hulls when you leave the yacht anyway.

07-15-2011 01:45 AM
Classic30 Hey Marty, thanks for your "alternate opinion".

If everything I've ever read is true, diesels much prefer not being used at all and then being worked really hard to idling for a few minutes each week - although presumably you aren't going to get seawater corrosion in a truck!

It is starting to seem like "best practice" is that, if you're going to run the engine at all, warm it up gently but quicker-than-idle and preferably in gear - and allow it to run (again in gear) for as long as possible (preferably an hour) before shutting down. Go for a spin if that's easier.

Originally Posted by blt2ski View Post
So with that in mind.........I would suspect red diesel in Oz is like here, do not run it in over the road rigs, as no road tax'es have been charged, BIG fines here in states, normal greenish color is ok in either off road, ie boat or equal, and over the road rigs. Red stuff is just a dye, so in reality, it can run in any combustion type motor.....
FWIW, diesel is actually a golden yellow colour over here... but biocide turns it red.

Originally Posted by blt2ski View Post
Off my rant a roo! by the way, what is a stick in ozzy boomarangoo speak?!?!?!?!?
"Stick"?? Here boy, fetch the stick!...
07-14-2011 11:32 PM
blt2ski SO what do them NA East coasters do in the winter with the blinking diesels? Run them while on the stands every two weeks or so?!?!?!?

Come now Camaron, I have to agree with fuzzy on this, youst worry WAY the blinking hell too much. I've got 5 diesels of different sorts and types, some sit for upwards of 6 months, run the heck out of em for a few days or a week or so, then they sit for a bit! Includes a dumptruck, bobcat, trackhoe, boat and pickup. Last two get run more than the others. Bobcat has all of about 1100 hrs since buying it in 99. What, 100 hrs a year? nothing but normal maintenance. Trackhoe has 1600, had 1100 when I bought it 7 yrs ago. Dumptruck, not sure on the hrs, it has 140K miles since I bought it in 92. Pickumup has 122K or there abouts, dash says over 4000 hrs in 6 yrs. Not sure on the hrs for the boat, it has not blinking temp guage, other than an idiot light/noise alarm, nor an hour meter, nor a tach, nor an anything but a key, start buttom, pull shut off switcharoo thingy.

So with that in mind.........I would suspect red diesel in Oz is like here, do not run it in over the road rigs, as no road tax'es have been charged, BIG fines here in states, normal greenish color is ok in either off road, ie boat or equal, and over the road rigs. Red stuff is just a dye, so in reality, it can run in any combustion type motor.....

Off my rant a roo! by the way, what is a stick in ozzy boomarangoo speak?!?!?!?!?

07-14-2011 10:52 PM
jrd22 God I love hearing you Aussies talk :-)) I try to run our old Volvo every couple of weeks when we aren't using the boat regularly. I let it idle for a few and then increase the rpm to about 1500 or so for about 5 minutes. Then I put it in forward (at idle) and let her run for 20 minutes or so around 2000. That seems sufficient to get the temp up to 180F (normal operating temp) for 15 minutes. A couple of minutes of idling for cool down and that's it. Our engine (MD 31A, 62 hp) won't come up to operating temp just running the alternators, it needs to be in gear to develop enough of a load (I suppose it would if I ran it long enough at a very high rpm), and running it in gear also lubricates the transmission and I like to think that it throws off any critters thinking about making the prop home.
07-14-2011 02:44 PM
Originally Posted by lancelot9898 View Post
That's what I do with my 1985 Perkins 4-108, however most years during the season(spring thru fall) I'm using the engine at least every week. During the winter I do not run the engine at all, but I put anti freeze in the raw water side to help prevent corrosion.
I think in general it is better to warm an engine up under light load than by idling. For example I have always warmed up my cars by driving gently for the first few miles, until the engine has warmed up. That will be a while after the coolant temperature reaches normal, as the oil temp will lag the coolant temp. The oil temp is a consideration as it's viscosity is a little high when cold. If it's a engine with an oil pressure guage, you can use that to tell when the oil has warmed up.

The idea of warming up by driving is that the engine spends less time in the damaging cold state where the mixture is rich, the oil is cold, clearances are too large, and so on.

So for the marine diesel, applying the same principles, let it idle for a short while, 20s or so, then warm it up in gear GENTLY - no more than half max rpm.
07-14-2011 01:05 PM
Stu Jackson When you use the boat, you run the engine.

When you're not there, the engine doesn't run.

Why hassle about any in between?
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