Marine diesel maintenance

[Bob Ohler]

Last night, I attended a West Marine seminar dealing with “Care and Feeding of Your Diesel Engine.” Harvey Smith of Annapolis Marine Diesel was the speaker, and he was nothing short of excellent! I believe that we could have kept him there until midnight asking him questions about our boat engines.

Some of the key points he made were:
1. Yanmar diesels should be run between 2400 and 3100 RPM’s. Anything more just burns excess fuel, and carbons the inside of the engine. For other makes of engines, the number is the “maximum published RPM, LESS 300 RPM’s.”
2. Don’t “baby your diesel.” Diesels need to be run, and run hard. Some of us that put maybe 25 hours or so on an engine over the course of the year, are not doing the engine any good. He says, start your engine and go! It doesn’t need to sit there and warm up, Check to make sure it’s pumping water and go. Don’t let them idle, say under 800 RPM’s.
3. Don’t run your diesel in its “rough spot.” The rough spot is when the engine vibrates. Increase the RPM’s to get the engine out of this state.
4. Proper engine to propeller shaft alignment should be done every spring, after launching and the tanks have been filled.
5. The oil should be changed TWICE a year.
6. DON’T use synthetic oils in our old engines. They will leak oil from every oil seal.
7. Change the transmission oil every year.
8. Replace the engine zinc as needed... probably once a year...maybe twice.
9. Replace the water impeller! Keep at least 2 spares on board with extra gaskets and extra cover plate screws! (What a concept!) Grease the new impeller when replacing it. Dish detergent is great for this!
10. Use the “cog type” V belts. They run cooler. Do not over tighten. 1/2” to 3/4” play is proper tension. Napa Brand XL belts denotes cog type.
11. Check for water dripping and or corrosion from the weep hole under the water pump. Use an inspection mirror for doing this. Water dripping indicates a bad seal in the pump. Replace it before the water finds its way to the crankcase!
12. Check your stuffing box. Use conventional packing with Teflon paste when repacking.
13. Install a Racor filter! He LOVES the Racor 500 series, but this looks enormous to me! He is not a big fan of the 120 series, but concedes it is better than the Fram system. (I just installed a Racor 120 this past weekend. It’s what the surveyor recommended. I also moved the location of the filter to the forward facing bulkhead, starboard side, just inside the engine access panel behind the
companionway ladder. It is very visible & serviceable there. Time will tell.) At the same time, install a fuel cut-off valve, if you don’t have one. (I don’t)
14. Use Biobor algaecide with every top-off of the fuel tank, and keep extra fuel filter elements on board!
15. For the first start of the engine (after a Winter storage) ... With the engine fuel cut-off pulled OUT, crank the engine for a few seconds...I figure 5 seconds or so. This will pre lubricate the engine after the oil has drained down out of the engine over the Winter.
Harvey Smith does business as Annapolis Marine Diesel, in Annapolis, MD. He can be reached at 410-267-9281

Hope all this helps with your Spring commissioning!

Bob Ohler
CD25D #2
“Aloha Spirit”



bobohler@chesapeake.net

[sam]

Bob, thanks for passing this good info along. I put a Racor 500 on my 4-108 on my CD 40 many years ago. When I got a load of bad fuel in the Bahamas I was very glad I had it. You can drain water, dirt easily. I change elements and have never had to bleed the engine. I shut off the fuel at the tank and top off the Racor with clean fuel. I've done this probably 100 times over the years and never had a problem. Also I find I only have to change the Perkins filter (which is located after the Racor once every 4 or 5 years). That's good news because you do have to bleed that filter and it is a stinky messy job.



n4uautoo@sprynet.com

[gates_cliff]

I have looked around on the board and haven't quite found an answer to my question, which is: What is the process for dewinterizing a Westerbeke.

Forgive my ingorance, I bought my CD 27 about 18 months ago. Based on recmmendations from the survey, I replaced the fuel tank, and the fuel lines from the tank. I was moving the boat from the location where I bought to Deale. So, to be sure I had done everything correctly I had Vosbury marine check the work and dewinterize the engine. The day I moved it, there was absolutely no wind and motored from the Annapolis Hinckley yard to Deale, the engine ran just fine. So, last fall, I had to be out of town on business for weeks on end, so had the yard, Shipwright Harbor, in Deale winterize the engine. So, at this point in my advanced years, I have never winterized or dewinterized a deisel engine. I'd like to do it myself, but want to be sure I do it correctly. Maybe I'm making too much out of this but just want to be sure I don't screw something up! So any help would be greatly appreciated.

Thanks

[bottomscraper]

It depends!

I do all my own work, for winterizing I disconnect the salt water
intake hose from the pump and install a short piece of hose that
goes to a bucket. I start the engine sucking fresh water from
the bucket for a few minutes to warm the engine. I am feeding
the bucket from a garden hose. After the engine warms up I let
bucket get almost empty and start filling the bucket with
no-toxic antifreeze. I let the engine run until the water coming
out the exaust is solid pink. This takes about 3-4 galllons on
antifreeze. I stop the engine.

Next I drain the dirty oil while the engine is warm. I change the
oil filter and refill with fresh oil. I loosen the belts. Remove the
salt water pump impeller. I drain all salt water lines, intake screen,
fridge heat exchanger (remove zinc from that). I change the Racor
fuel filter and engine filter (every other year). I then spray a little
CRC Marine Engine-Store into the intake (probably does
nothing but makes me feel good). I drain the transmission and
fill with fresh fluid. I then remove any old "engine diapers" and
clean out under the engine.

In the spring I check all fluid levels. I replace the belts and tighten
and install a new salt water impeller (with some glycerine as
lube) I inspect for loose bolts, wires, leaks etc. We then run
the engine with the bucket and hose. (We keep the boat in our
yard during the off season so we prefer to make sure the engine
will start and run before we launch. If we were in a boat yard we
might just skip this step.) We check the oil filter for leaks. I then
replace the fridge zinc, reinstall the salt water intake screen and
run some fresh water from a hose back through the intake hose
to fill everything up (intake filter, fridge heat exchanger, hose)
before reconnecting the hose on the salt water pump. I do
this so the impeller doesn't run dry. If I change the engine
fuel filter I will need to bleed the engine before running.

I then clean under the engine again place some clean "engine
diapers" under engine. (Bleeding can get messy.)

The Perkins doesn't have an engine zinc but if your engine does
you should replace that also. Also check you prop zinc.

[Zeida]

BOB, Thanks for taking the time to print the diesel engine service tips. They are wonderful.

[cguthrie]

I'm going to print this out and keep it aboard. Thank you so much for this helpful post. Cliff

[Bob Ohler]

Cape Dory Sailors All:

I am glad that an old post from a couple of years back is still useful today.

Fair winds,

Bob O.

[Sea Hunt]

Hello Bob:

I have printed it and stored it for the day, hopefully soon, when I will have a Cape Dory 25D with a Yanmar 1GM.

Thanks.