No marks on dipstick (yanmar 2gm20f), how high to fill?

[paulg222]

Its my first season with this boat/engine, its a 1982 era yanmar 2gm20f diesel. The dipstick for the lube oil has virtually no marks on it. There are 2 small holes in the dipstick, one close to the bottom, the other close to the top. There is a very very slight horizontal mark a bit above that lower hole. Unclear if that horizontal mark means anything or if it indicates high or low.

Can anyone with a yanmar 2gm20f let me know how high up on the dipstick oil should go? Thx.

[StuM]

There are at least two other 2GM20 dipsticks which don't match your description. But the physical distance between the minimum and maximum levels won't change. The lowest hole on yours will be the minimum level. Whether the maximum level is the top hole or the mark above the lower hole depends on the spacing. Compare yours to these two.

[a64pilot]

I would suggest pumping out all of the oil, be sure move the tube in and out until you get it all, then put the correct amount of oil in by measure and see where it falls on the stick as a way to validate the stick.

[Olmoose]

Caution, I would not drain out old oil and refill with the proper specified amount of oil, if your engine is mounted on a slant (as most are) and a drain plug is inaccessible.

On my 3M Yanmar it is almost impossible to fully evacuate the old oil. As such you will most likely over fill it. No drain as it were, I use a pump. Just sayin..

[GordMay]

Greetings and welcome aboard the CF, Olmoose.

Note: The (spec'd) 2.0l oil capacity only corresponds to the "full" dipstick mark, when the engine is installed at the recommended 8 degree rake angle (15 deg is max angle).

[Boatyarddog]

Originally Posted by paulg222

Its my first season with this boat/engine, its a 1982 era yanmar 2gm20f diesel. The dipstick for the lube oil has virtually no marks on it. There are 2 small holes in the dipstick, one close to the bottom, the other close to the top. There is a very very slight horizontal mark a bit above that lower hole. Unclear if that horizontal mark means anything or if it indicates high or low.

Can anyone with a yanmar 2gm20f let me know how high up on the dipstick oil should go? Thx.

Gord May gave the best answer.
But... Here's the link. http://j30.us/files/yanmar-manual.pdf
2.0l at 8 degrees angle
Maybe slightly different according to your actual installation.
Don't overfill, it beats the oil into a foam, you then get lowered oil pressure.
In general no lower than the bottom hole, no higher than the upper hole.
Cheers,
SV Cloud Duster

[TideTime]

My Yanmar is a 1GM10 and I initially had a difficult time determining the fill level on dipstick which is probably similar to your 2GM. Actually there is a mark indcating the upper level on the dipstick for the 1GM10. Boatyarddog mentions one reason you do not want to overfill the crankcase. However, there is another more significant reason for preventing an excess amount of oil and that is the possibility of a run-away diesel. The diesel will have no problem running on oil only and simply shutting off the fuel supply will not serve to shut down engine; you would have to shut off air supply which, depending upon location of air intake, could be difficult and costly if not accomplished prior to engine damage.

[a64pilot]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Olmoose.

Note: The (spec'd) 2.0l oil capacity only corresponds to the "full" dipstick mark, when the engine is installed at the recommended 8 degree rake angle (15 deg is max angle).

On most engines the dip stick is mounted in the middle of the sump, so unless attitudes are out of spec it should still read close or very close, it was meant as a way to verify the stick, I’ve seen more than once the incorrect stick in an engine and there are even aftermarket sticks that you mark.
If you put the correct amount of oil in and it isn’t very close to the stick mark, you need to investigate, not just think well the stick mark must be correct, cause it might not be.

Now of course some engine manufacturer could have I guess not realized that their marine engines are mounted at an angle and not put the stick mid way so that an angle didn’t change the level at the point of measurement, but I’m trying to think of any engine I have had that the stick wasn’t centrally located and coming up with a blank.

I’d assume that is something that engine manufacturers figured out long ago.

But the degree it’s mounted at is easy to measure too, even the apps on smart phones I’ve found to be very close.

[George DuBose]

Well, my 2004 3GM30F Yanmar's oil dipstick in the transmission has NO marks or holes. I just keep the bottom inch wet.

I even ordered a new dipstick and it also came with NO markings at all.

I do love my Yanmar though. ;>)

[a64pilot]

Originally Posted by George DuBose

Well, my 2004 3GM30F Yanmar's oil dipstick in the transmission has NO marks or holes. I just keep the bottom inch wet.



I even ordered a new dipstick and it also came with NO markings at all.



I do love my Yanmar though. ;>)

I think you got a “universal” stick, I believe your supposed to mark it yourself and the manual may specify exactly where the marks go.
It may be the maintenance manual and not the operators manual though.
I don’t think that’s uncommon.

[GordMay]

Originally Posted by a64pilot

On most engines the dip stick is mounted in the middle of the sump, so unless attitudes are out of spec it should still read close or very close,...

From the Operation Manual, to which Boatyarddog so kindly linked:
☞ http://j30.us/files/yanmar-manual.pdf

3-2.1 Preparation of the engine foundation plate (page 7)
The installation angle will differ with the vessel configuration and installation location of the engine. The most suitable installation angle is 8 degrees and the maximum installation angle is 15 degrees.

6.2 Supply of lubricating oil (page 21)
Volume of tube oil corresponding to the upper mark on the dipstick (with an installation angle of 8°)

[jmschmidt]

By Gove you've freaking got it mate.

[paulg222]

Originally Posted by Boatyarddog

Gord May gave the best answer.
But... Here's the link. http://j30.us/files/yanmar-manual.pdf
2.0l at 8 degrees angle
Maybe slightly different according to your actual installation.
Don't overfill, it beats the oil into a foam, you then get lowered oil pressure.
In general no lower than the bottom hole, no higher than the upper hole.
Cheers,
SV Cloud Duster

Thanks but not overfilling is what I'm worried about. The upper hole is quite high on the dipstick, and other people talk about just covering the bottom inch. My top hole is much more than that.

Someone with yanmar 2gm20f, send a pic