Routine Engine Maintenance

Duke 7184 · #1 (**permalink**) 02-21-2007

Weather permiting, it's about eight weeks till spalsh down. One of the first things I want to get done is changing the oil in the engine. The engine [a YANMAR 3GMD] runs good (at least it did a year ago when I started the boat's renovation). The boat is new to me and there are no maintenance records indicating what type of oil had been used in the past. The engine manual calls for either a 20 weight or 30 weight oil depending on the temperature. I'm considering a multi weight. I figure the engine is 25 years old what harm could it do?
I welcom your comments.

camaraderie · #2 (**permalink**) 02-21-2007

Duke...I always used 30W in my old Yamaha with no problems. Be sure you get DIESEL grade oil as specified in your manual and not just 30W automotive. (Just mentioning this since you said the boat is new to you.)

PBzeer · #3 (**permalink**) 02-21-2007

I concur with camaraderie, particularly on Diesel Grade Oil. I use 30w in my Yanmar (didn't even know Yamaha had a marine diesel ) as well and my engine is 23 years old. Don't know how often you motor, but since you have no records, I'd change it again after about 50 hours, with filter. Just a little extra insurance.

camaraderie · #4 (**permalink**) 02-21-2007

PB...yeah...a typo...but actually I have seen a Yamaha OUTBOARD diesel!!

sailingdog · #5 (**permalink**) 02-21-2007

Cam-

That would probably be a Yanmar Diesel Outboard... they make two models IIRC. I don't believe Yamaha makes any marine outboard diesel engines...

Duke 7184 · #6 (**permalink**) 02-21-2007

Thanks for the input. Though I am not very knowledgable about diesel engines, I do know to usethe proper type of oil. Just for the info.. The YANMAR 3GMD is a three cylinder, 20 HP inboard diesel. The engine doesn't have a heat exchanger, just stright raw-water cooling. This one even has a hand crank as a backup for starting.

camaraderie · #7 (**permalink**) 02-21-2007

Dawg....hmmm...must be going senile. I stand corrected.

tdw · #8 (**permalink**) 02-21-2007

Quote:

Originally Posted by Duke 7184

Thanks for the input. Though I am not very knowledgable about diesel engines, I do know to usethe proper type of oil. Just for the info.. The YANMAR 3GMD is a three cylinder, 20 HP inboard diesel. The engine doesn't have a heat exchanger, just stright raw-water cooling. This one even has a hand crank as a backup for starting.

Duke,
Before you fire her up hand crank her a few times to get some oil circulating, particularly if it's been cold in your area. This may be obvious but it's a good idea nonetheless. Might be a good idea to fit a new water pump impellor and oil filter as well.
TD

SailorMitch · #9 (**permalink**) 02-21-2007

FYI. The fine folks at Torresen Marine (Yanmar dealers) have said that the newer multi-grade oils, such as Shell Rotella 15-40 (although I may have those numbers wrong, maybe 15-30?) are an upgrade in oil for these older diesels. I changed to the Shell Rotella in my boat with a Yanmar 2GM20F when I bought it 3 years ago and the engine runs fine. Check www.marinedieseldirect.com for more info. Torresen also has a bulletin board there for Q&A's as well.

paulk · #10 (**permalink**) 02-21-2007

We have been very careful to not to mix different types of oil in our raw water cooled 1982 Yanmar 3GM. When we added some oil, mid-season, mid-cruise, the mechanic we went to took it upon himself to go find a match to what we had put in earlier in the spring, and NOT use the multi-grade stuff he had out on display for sale. If Yanmar says the new, multi-grade is OK, or better, it probably is, IF you are putting in all new oil. Mixing different grades or brands may not be, as far as we can tell.