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  Topic Review (Newest First)
09-09-2013 04:12 PM
Re: Confused about which oil weight to use

I ended up using Delo 400LE 15W-40 oil. I think it had straight 30 weight before. Starts better, and runs noticeably quieter too.
08-08-2013 06:13 AM
Re: Confused about which oil weight to use

Sounds like a great idea. I will definitely do that! I put the thermostat in yesterday (which it probably never had one in it); and ran the motor for 10 min at 2300 rpm (no load), then cooled down at idle for 5 min. and she ran warm-to-touch; at both speeds. -the motor sounded like normal, and I had good water flow out of the exhaust. So far so good. It starts on first turn of the key, everytime. Thanks!!
08-08-2013 03:12 AM
Re: Confused about which oil weight to use

Assuming your oil sample report is good, it would still be worth monitoring your engine's health for a while.
Buy or borrow one of those filter cutters (like a can opener). If you can't get one at an auto parts store, any place that sells tools to aircraft mechanics will have them. They are cheap enough.

At next oil change (which may be worth doing early - say after 50 hours), when you pull the filter, drain it for an hour, then cut it open. Lay the paper element out on a sheet of white paper under a bright light. Any metal fragments will show up. If some are present, send oil to same lab that did your last one for another report. If no metal visible, you are probably OK.

Either way, if the engine is still running OK, pull top off cold beer and chill out......
08-07-2013 09:42 AM
Re: Confused about which oil weight to use

Sounds like a great idea! Thanks, the oil analysis will come back in a week.
Hopefully, its not in too bad of shape..... Thanks again!
08-07-2013 09:08 AM
Re: Confused about which oil weight to use

Good advice about flushing with fresh water. If it's going to sit for a while, it might be a good idea to flush with glycol or regular anti freeze to further protect the water jackets in the block. Whenever you lay the boat up for a period of time it's also a very good idea to stuff a rag in the exhaust so air can't get into the valves through the exhaust pipe and cause corrosion.
08-07-2013 07:33 AM
Re: Confused about which oil weight to use

DixieJ, a very good idea to have your engine oil analysed. Hopefully it will give you peace of mind. The fact that the engine seized AFTER you shut it down may have saved it. They do heat soak a bit after shutdown - that is one reason to idle them for five minutes after a hard run.

The Yanmar GM series are very robust and survive well even in salt water. With the two that I have owned over the years I have probably exceeded 3000hours between them. Neither had hour meters and I tend not to worry about hours anyway - more about having a calendar-based maintenance schedule e.g. oil and filters every six months, zincs at 12 months, impeller at 18 months etc.

On both boats, for less than 50 bucks I fitted a 'T' piece and shut-off valve in the raw water inlet line to which I attach a garden hose for an end-of-season freshwater flush (the boat stays afloat in salt water all year and we don't have a freezing problem here). If you do this, it is absolutely ESSENTIAL that you start the engine on salt water and then only put fresh water in at a fairly low pressure, then shut off the salt water intake and regulate the fresh flow carefully so you don't over-pressurize. You will need to look at the exhaust outflow to gauge this. Run it in gear at 1500 to 2000 RPM for a good 15 to 20 minutes to give it a good flush, keeping a constant eye on the exhaust outflow. You want it to get up to operating temperature. Then with the engine at idle, after a few minutes to allow it to cool down, shut off the fresh water first then shut the engine down, NOT the other way round (unless you want water in the cylinders!). By taking the hose off at the dockside tap first, by the time I get back to the engine it has drawn most of the water in the hose through and I shut it down immediately. You don't want to run the impeller dry.
08-06-2013 10:20 PM
Re: Confused about which oil weight to use

WOW, such wonderful responses and insights from so many experienced sailors! I love it. I am learning so much about my motor! Simply Awesome.
This 3GMD YANMAR (raw water) 20 HP at 3400; 1981-83 built motor was installed on the boat (newly rebuilt) in 2004. I doubt if it has more than 300 hours on it. 150 hours have been put on it over the last 14 months. One 14 day trip from sarasota to Key West and Back. And recently, the trip up to Tampa, and back 20 hours over 5 days. So, As I mentioned earlier, I discovered that there was no water thermostat. I just bought one today, and I am hoping that the motor runs right when I put it on. The impeller is new, and the old one was good. It is my back up now. I am wondering if while sitting at the Venice dock, if some plastic bag didn;t get sucked toward the intake and prevent water coming in through the thruhaul. Because, after running the motor for 22 hours on new oil and filter, she has not gotten hot, or shut down, since that time. I am sending in a oil sample for analysis, just to see if there are any major issues that are derived.
Thanks to all for your wonderful help. I will keep you posted on how it goes.
(Oh, I checked the raw water strainer, and it flushed water out when I opened the thru haul seacock, so I am getting plenty of flow. It was clean).
08-05-2013 08:23 PM
Re: Confused about which oil weight to use

I can remember having salt water cooled Chrysler Crowns and Royals in some of my old boats. Those engines lasted decades with salt water cooling. Of course, the castings were twice the thickness of modern motors and made from non-recycled cast iron. After quite a few years, they would usually succumb to graphitization, crystallization of the iron, induced by salt water electrolysis. A lot of the new power boat V8 automotive conversions are very thin castings. I can't imagine them lasting more than a couple of years if cooled with salt water. The nice thing about the little Yanmar diesels is that they are more like the old straight 4/6/8 blocks of the past.
08-05-2013 08:08 PM
Re: Confused about which oil weight to use

Good day avicola...

Part of that discussion would obviously be how old the boat/engine when one got it. Since I am a poor man... any boat or engine I get is about 20 or 30 years old. If one buys new and trade off every few years then its a moot point. I am not in the category, although the concept of disposable everything just always seemed so wasteful to me.

On the two engines prior to this latest one they were raw cooled in salt water... pretty much killed the engine's cast where as all the main mechanicals were totally rebuildable, refreshable, or simply just fine. I guess killing a block or a head casting simply because one can afford it just goes against my grain I guess. Cost effectiveness is minor up to a point. See, I'm from the school that proper and complete maintenance and non abuse will let an engine more or less be able to keep running almost indefinitely. It's likely I'll get 400k on my 3/4 ton V8 and better than a million on my cummins... before their first rebuild. marine is no different... take care of them and they will take care of you. Yea, manufactures and their service departments hate people like me.

The 1975 S30 Farymann antique I recently purchased is raw water cooled but was in the fresh water of the great lakes most of the last 20 years... cooling passages are in good condition... compared to 30 year old ones that came out of FL or the Chesapeake, its a diamond.

As one who restored and showed true antique engines for quite a few years... and take what many would see as just a hunk of rust and have it running inside a week or two (depending on if it was complete and you have to know what to look for), engines from the 70s and 80s are very modern in comparison to the teens and 20s. It just seems disrespectful to any engine that way by letting them just rot from the inside so to speak by killing the casting with salt water. Someday they will be 90 or 100 years old too. My oldest show engine is a runnable 1907, yes a 105 year old Callie Perfection 2 cyl inboard marine. I get a special smile bringing a 80 or 90 year old engine back to life, running for the first time after maybe 60 or 70 years of neglect.

I haven't priced heat exchangers and an extra pump yet.... maybe I won't convert if its too expensive. But then I am not sailing (yet) in saltwater only the Great Lakes. It will be converted before I do saltwater however, on my principles. The heat exchanger is disposable, the engine is not in my mind. You all are welcome to do as you like... its a semi-free country. Its just my opinion.

08-05-2013 06:09 PM
Re: Confused about which oil weight to use

Drifting off subject a little, but to revive the old debate about whether to convert a raw water engine to fresh cooling is worth the money.
Personally, I don't believe it is. Raw water cooling is simple and cheap. The key to long engine life is frequent use and flushing with fresh water prior to any lay-up. If you are not using the engine frequently, a fresh water flush every time you shut down would be a good thing to consider. Because they don't run as hot as fresh water cooled engines, they may wear a little faster, but hey, just how many hours are we talking about over, say, a 15 year life?

Fresh water cooled engines still have salt water coming in to the heat exchanger and being discharged via the exhaust, so corrosion will occur in those components anyway. Heat exchangers usually have zincs to replace, just like those in the block of the salty engines. Heat exchanger tubes get salt-encrusted and weed in them, just like their salty mates. The difference in engine life might be 15 years for the salt (which I achieved with a Yanmar 2GM and it was still going strong when I sold it) and 20 years for fresh. Plus more hoses and another pump to deal with, and possible heat exchanger replacement at the 10-15 year mark anyway, so would the additional cost of purchase and maintenance be fully recovered in that time span? About break evens whichever choice you make, I guess.

Sure, if buying a new engine, I would consider fresh water cooling if I thought that I would be keeping the boat for more than 15 years. My current 2GM is now 6 years old and there is at least another year in the original exhaust elbow - thanks to continuous summer use and end of season fresh water flushing.
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