R21 Engine oil type

[bjp447]

I have a R21 with the older 2GM20F Yanmar diesel and I live in Atlanta GA which is not known for
its Marine diesel dealers. I want to change the oil before I pull it for storage and I have no clue what
Brand/weight type oil I can put in it. I know it needs to be a diesel oil but I won't find it thru a boat dealer
here. Can I use an auto diesel oil from a NAPA or whatever. Any ideas on what I can use. The diesel guy who had been changing it left, and there is no contacting him. Any help is appreciated.
s

 

[Capt’nKarl]

I use Pennzoil 15W40 Marine oil in my 21 EC 2009 Yanmar 3ym30. I live in Florida so don't have to worry about weather getting too cold in the winter. This is a good marine diesel oil. Available at auto parts stores or West Marine. You can also get 3 gallons on Amazon for about $66.

cheers,
Karl

 

[fran uteg]

Good afternoon folks ....... another great diesel oil is Shell Rotella "T" Diesel, also available at Walmart and most auto supply stores. I use Rotella T in both the launches 2GM20 and the tug's 3YM30 ..... since both boats are in Georgia I use a 15w40 and have been pleased with the performance. If your 2GM20 is a high time engine you might consider the Rotella "T"5 which is a partial synthetic oil with higher abrasion resistance ........ hope this is of some assistance ......... Fran 😉

Just a quick afterthought ....... on my 2GM20 I use a Fram 3593A oil filter ...... the Fram has a slightly thicker case and can handle the possible higher pressures of the little diesel.

 

[sheral]

I am a huge fan of Rotella diesel oils. If you call Shell's 1-800 number they can ensure it meets/exceeds your specific requirements. I am sure it will...

 

[SGIDAVE]

The MARINE oils I have seen are for GAS engines. I'm not saying there are no "marine" diesel engine oils out there - just that I've not seen any.

DIESEL engine oils have a special designation as found on DELO, Rotella, etc.

For your Yanmar, you should use the oil type recommended in your MANUAL; the brand is less important. For Example, the operators manual for current Yanmar 3YM engines states to use engine lubricating oils rated:

Type API, Class CD, CF, CF-4, CI and CI-4

So, you can use any brand oil you like with the above designations. Note there is no "marine" specification.

I'm sure you can "get away" with using almost ANY oil, but MY OPINION is to use the oil/s specified by the manufacturer until the engine is no longer warrantied - thereafter use similarly graded oils - switching to synthetic if you like to use spendier products. The new Volvos may specify synthetics from new; the small Yanmars don't.

dave

 

[bjp447]

Good afternoon folks ....... another great diesel oil is Shell Rotella "T" Diesel, also available at Walmart and most auto supply stores. I use Rotella T in both the launches 2GM20 and the tug's 3YM30 ..... since both boats are in Georgia I use a 15w40 and have been pleased with the performance. If your 2GM20 is a high time engine you might consider the Rotella "T"5 which is a partial synthetic oil with higher abrasion resistance ........ hope this is of some assistance ......... Fran 😉

Just a quick afterthought ....... on my 2GM20 I use a Fram 3593A oil filter ...... the Fram has a slightly thicker case and can handle the possible higher pressures of the little diesel.

Hi and thanks for the advice. I am thinking of an EC once I sell the R21. My wife agrees since the EC is a bit fancier. My thing is I want the larger engine and more cabin space for overnights. You have the 18 hp and the 28 hp my question is does the bigger engine make a difference. The 2GM20 is happy at about 2800 rpm and 5 to 6 knots. does the 30 do any better? and I understand the EC has a 4 bladed prop vs the 2 blade on the R21 , any thoughts on that
Thanks again to everyone for their input

 

[Captain Nice]

I get 6 knots at around 2100rpm and 1/2 gal/hr fuel burn with the 30hp Volvo Penta (clean hull, calm conditions, 2 people on board).

CN

 

[fran uteg]

"S" in answer to your question, its rather hard to compare apples and oranges ........ the launch is narrow (just under 6 ft), full displacement, and 21 ft at the water line. I run the 2GM20 at 1400 rpm, turning an Ellis 15x12 three bladed prop, which results in 6mph. At 3650 rpm the launch will do 13 mph. The R21EC has the 3YM30 and at 2500 rpm, turning an Acme 224, 12X15.5 four bladed prob, and will run at 7.5 mph. The 3YM30 is pushing a lot more boat and you can feel the torque. At WOT (3200 rpm) the 3YM30 will move the tug at just under 10 mph. Overall the 3YM30 is a smoother engine than the two cylinder, but the little 2GM20 burns just over a pint of diesel per hour, and at 1400 rpm it doesn't vibrate enough to spill the wine and cheese, which is the main use of the launch. 😀 ........ Fran

 

[bjp447]

Thanks, the wine and cheese are important. I really enjoy my R21.
I downsized from larger sailboats and have really enjoyed turning the
key, pushing a button and chugging away, while still feeling like I haven't
gone over to the dark side. My sailing club likes having the tug in its midst