R21EC Oil Change Types and Location Yanmar

bjp447

Well-known member
Joined
Mar 8, 2011
Messages
116
Fluid Motion Model
C-24 C (Sterndrive)
Vessel Name
Sand Dollar
I am getting ready to change the oil on my 30hp Yanmar on the R21EC (first time, for me at least)
My manual says Type should be Rotella 10 w - thats what I used in my R21
1. Does 10 w sound right?
The manual emphasizes that the Trans oil is different that the engine oil but does not give a type
2. Anyone know what type of oil goes in the Trans
On the R21 I drained the engine oil thru the dip stick tube with my extractor from West marine
and replaced the oil thru the oil the oil screw top on top.
The Yanmar 30 has a oil opening on top but also one marked oil right above the Dipstick towards the
front lower part of the engine,
3. Anyone know what the lower space with the oil cap is for?.

Thanks
 
The lower oil cap is only there for access in other installations. I use Shell Rotella T6 for the engine and a good 30 weight for the transmission. Never had any issues. I pump out through the dipstick tube. Should get 3 quarts.
 
Good morning Sand Dollar,
I have a 2009 21-EC with the 3 cylinder Yanmar Diesel engine. I use PENNZOIL Marine 15W-40 oil in the engine. In the transmission I use Delo 400 Heavy Duty Motor oil SAE 30. This oil does not contain a detergent since there is no filter in the transmission. There are two entry points on the engine for oil replacement, one on top and one on the side. This engine is used in multiple boats and configurations and depending on the engine placement in the boat they provided two oil fill locations for access. Changing the oil is fairly easy on this engine.
Cheers!
CaptnKarl
 
Thanks - answers my questions

One last one - what oil filter do you use that I can get
at auto zone or napa or ?
 
bjp447":uwtun8vj said:
I am getting ready to change the oil on my 30hp Yanmar on the R21EC (first time, for me at least)
My manual says Type should be Rotella 10 w - thats what I used in my R21
1. Does 10 w sound right?
The manual emphasizes that the Trans oil is different that the engine oil but does not give a type
2. Anyone know what type of oil goes in the Trans
On the R21 I drained the engine oil thru the dip stick tube with my extractor from West marine
and replaced the oil thru the oil the oil screw top on top.
The Yanmar 30 has a oil opening on top but also one marked oil right above the Dipstick towards the
front lower part of the engine,
3. Anyone know what the lower space with the oil cap is for?.

Thanks

Hello Bruce,

There's something missing from your Yanmar manual. You should NOT use "straight" 10W oil in your diesel! The info below is from the Yanmar manual (the bold part being most pertinent):

-API Service Categories: CD or higher

-TBN value: 9 or more

-The oil must be changed when the Total Base Number (TBN) has been reduced to 2.0.

-TBN (mgKOH/g) test method: JIS K-2501–5.2–2(HCI), ASTM D4739(HCI)

-Recommended SAE Viscosity: 10W30, 15W40. Engine oil 10W30 and 15W40 can be used throughout the year.

-NEVER use API Service Category CG-4 or CH-4 oils.

YM Series Operation Manual page 27
© 2009 Yanmar Marine International

Under most circumstances, Ten weight oil will be TOO LIGHT for your diesel and will not properly coat the moving parts. I advise you drain and refill with proper oil ASAP. I would not operate the engine with the straight 10W oil....unless you operate exclusively in arctic conditions.

Note that "marine oil" is not necessarily appropriate for the diesel engine. In most cases, when you read the label, you will see that it states the oil is for GAS engines. If the oil container label does not state that it is for DIESEL engines, don't use it.

From page 29 of the Yanmar manual:

Marine Gear Oil Specifications
Use marine gear oil that meets or exceeds the following guidelines and classifications:

KM2P-1 (S), (G) or (GG):
-API Service Categories: CD or higher • SAE Viscosity: #20 or #30

So, the marine gear is the ONLY place single viscosity oil is appropriate for the boat. And, you can use ANY decent 20 or 30W oil...whether the label says for GAS or Diesel does not matter (I am referring to the "gear" or Transmission now).

If you do an internet search, you will find the Yanmar operation manual which you can download. And KEEP.

This reminds me...my boat is due for maintenance next month...

dave
 
Dave thanks - did not have the correct Yanmar manual (downloaded from the internet)
Any suggestions on the oil filter?
Bruce
 
bjp447":2i5ophas said:
Dave thanks - did not have the correct Yanmar manual (downloaded from the internet)
Any suggestions on the oil filter?
Bruce

Hello Bruce

If you know the Yanmar OEM oil filter model or part number then you can search for "equivalent " models. I think I used a Fram filter this past year. I'm away from the boat now and can't get numbers now.

Dave


Sent from my iPhone using Tapatalk
 
Bruce,
The Yanmar oil filter part number is 119305-35151.
Cheers!
Karl
 
Still confused - went to auto zone and looked for 30W Gear oil, for the transmission.
They looked at me like I was crazy.
They had 90 w gear oil to 140 w gear oil and lots of 30 w engine oil, but somehow 30w gear oil
did not ring any bells. Rielly's and NAPA were kinda the same. If I found the right info 30 w engine oil
is equivalent to about 80w gear oil (lube). Even the manual kinda leaves that out.
So when you say use any good 20 or 30 w oil in the transmission do you mean any oil ie engine oil,
or something specifically labeled gear oil. I called Yanmar St Pete and they couldn't give me a good
answer, They said go to a yanmar dealer. Lots of luck with that within 300 miles of Marietta GA.
All I want to do is change the transmission fluid in the R21EC, it should not be this hard.
 
As noted in previous posts, the Marine Gear in the 21EC does , indeed, take 20 or 30 SAE motor oil. (I prefer 30)......anyone telling you to use 90 or 80W90 is talking about a Yanmar with the Sail Drive.
 
This is what I use
Water pump impeller- F4 series #09-810B-1
Oil filter Mann #W67/1 or Wix#51365
Fuel filter Wix #33262
Air filter yanmar 128270-12540
Racoe filter #R11t-0705
I use the same oil that I use in my tractors for the engine and transmision, not sure if this is recommended but I've put up a lot of hay and have lots of hrs on both tractors, most parts I get from Amazon or the local auto store, and my ford/New Holland dealer, I try to keep it simple and inexpensive. I'm sure some will disagree but it worked for me
Oil is Mastergold engin oil sea 15W-40cj-4 that I get from my local new holland dealer
Please double check my numbers as I have fat fingers and spell check does not always agree with me
Bob
 
This is what I use
Water pump impeller- F4 series #09-810B-1
Oil filter Mann #W67/1 or Wix#51365
Fuel filter Wix #33262
Air filter yanmar 128270-12540
Racoe filter #R11t-0705
I use the same oil that I use in my tractors for the engine and transmision, not sure if this is recommended but I've put up a lot of hay and have lots of hrs on both tractors, most parts I get from Amazon or the local auto store, and my ford/New Holland dealer, I try to keep it simple and inexpensive. I'm sure some will disagree but it worked for me
Oil is Mastergold engin oil sea 15W-40cj-4 that I get from my local new holland dealer
Please double check my numbers as I have fat fingers and spell check does not always agree with me
Bob
 

This is the oil that I use for all my diesel engines, I have over 6,000 hrs on little tractor and still running strong, I think the most important part is to keep a good regular change wether every 100 hrs or once a year, which ever comes first
 
Bob and everyone else thank.
I am going to buys some 30 weight motor oil for my 3ym30's transmission
and it will just have to live with it.
My understanding is the only difference between gear oil and motor(engine) oil is no
detergents in gear oil. I just wish the manual had just said. Just put a good 20 or 30 weight
motor (being the key word) oil in the transmission, but I suppose it is Yanmars way of us becoming
more knowledgeable DIY boat mechanics.
Again thank you - on to the next challenge
Bruce
 
Ah, yes, Bruce , the DIY phenomenon......what better boat than a 21 for DIY ????
Someone else here once noted that in his fantasy world he could afford to buy whatever boat he wished.....and afford to have all maintenance performed for him.....and afford to voyage whenever and where ever he wished..........but then he awoke from his dream.

As for reality.....your DIY skills may save the bacon one day,when there is no one available to come to our aid..........plus we always have TugNuts.......
 
I’m confused about the different types of oil as well. I want to replace both the motor oil and the gearbox oil. I have a 3YM30 and my operations manual (copyright 2004) doesn’t provide a gear oil recommendation. Neither does the service manual.

I bought the boat used and it’s my first time doing an oil change. The previous owner made some notes in the back of the manual. Last oil change they used 30W Chevron Delo 400. The spare oil jug that was on the boat when I bought it was Delo 400 SAE 30.

Question: Is 30 W Delo 400 the same thing as Delo 400 SAE 30?

Based on what I read on this forum, and what was written in my manual from the previous owner, I’m going to use Del 400 SAE 30 for the motor oil, and then use Delo 400 15W-40 for the gearbox. Does that sound about right?

Also, is there a motor oil drain plug or petcock to drain the sludge (after done siphoning oil out of the dipstick hole)?
 
Boris....you have it reversed.....use the multi weight in the motor...use the straight 20 or 30 weight in the gear box...
 
Awesome, thank you so much! I had a suspicion that was the case.

I went to the service manual (not the operations manual) and now I see it. Page 20 (4R1) and 21 (5).
 
Back
Top