Yamaha Oil Level

[Rocky Lou]

Like a lot of folks, I've put more hours on my boat due to the Pandemic. My normal haul out is spring time and an oil change couldn't wait as I was about 130 hours. I pumped out both engines, changed the filters and carefully added oil until I measured just below the top hole on the dipstick. I display pressures on Garmin which read fine and there were no alarms. After running a few weeks, I decided to check the oil levels and both readings were 1.5 - 2 inches above the top hole. I understand that oil may not have been completely pumped out...but, I carefully read *both* dipsticks while filling. I plan to head over today and pump out until reading are back between the holes. Any thoughts why both are now so high after running?

 

[KennyMarrs]

Rocky Lou,

My only thought would be the oil level didn't settled all the way down before checking the dipstick. I know when I do my truck I give it 30 minutes after I've added the oil before checking the dipstick. I'll do an initial check but still wait to see if any more oil settles.

-Kenny

 

[KKRCRACE]

Hi, I have had the same problem with my 300 Yamaha. I have been told by Yamaha that the oil level is rising because of fuel. I could smell the fuel in the oil when we changed it. We are working on the theory that I have not been running the boat hard enough and the motor has not sealed properly. I am on the Chesapeake bay and for my C24 it’s to rough to run hard most of the time. I now try to run it hard for a little while each time I go out if possible. It does seem better when I do run hard. I should have done it after break in.
KKRCRACE

 

[Rocky Lou]

Thanks for the replies. I pumped out about one quart each and am back between the guides. I was ready to attribute the whole thing to settling (thanks Kenny) and along comes KKRCRACE...that's way above my pay grade. I'm hoping BB and a few others who understand Yamaha systems will weigh in now. BTW, I also am speed limited in NorCal offshore.

 

[knotflying]

and carefully added oil until I measured just below the top hole on the dipstick.

How much oil did you put in? On my 300 Yamaha when I change oil and filter I add 7 quarts and the oil level is between the two holes.

 

[BB marine]

If this is your first oil change and you pumped the oil out. I would have recommended the use of a container with qt marks to measure the exact amount of oil pumped out. Knowing what the oil capacity is minus the amount pumped out lets you know how much to add . Only add the amount pumped out. After changing the oil add the amount that was pumped out. Install a new filter. Start the engine for a few minutes then use the procedure below. This helps "burp" the oil and drain properly for a proper oil level check. Always check oil level with the engine in a level position. (A true level plane).

I would guess that when you filled the oil at the oil change you ran the engine shut it off then added oil to the full mark and there was still oil that was not fully drained. Did you trim it up to allow oil to drain as per instruction below?


When changinging oil for the first time this gives you a base line for how much oil to add after a oil change. Always confirm that the engine is in the same position when pulling oil from the crank case and add oil based on the amount removed to give you a baseline to start with then use the instructions below to check it.




Checking your oil level.

The oil level check procedure for your Yamaha four-stroke outboard is a bit different than the procedure for your car. It’s easy to get an accurate reading if you follow this procedure:

Start and warm the outboard to normal operating temperature, then shut it off. Stop the outboard.
Tilt engine up halfway and allow to rest for 5 minutes to thoroughly drain the oil back
into your outboard’s crankcase.
Trim the outboard back down to level.
Tip: You can place a small level on top of the anti-ventilation plate to help you determine when to stop.

Pull the dipstick, wipe the oil from it, and re-insert it in the crankcase. Then pull the stick again
and check the oil level. This helps ensure proper venting for accurate indication.
At the proper oil level, the oil should be halfway up crosshatch pattern on the dipstick.
Tip: The top and bottom of the crosshatch pattern on the dipstick do not represent “high” and “low.” The correct oil level indication is at the mid-point of the pattern. Use caution when filling or adding oil. Yamaha four-stroke outboards have a tapered oil sump design (smaller at the top than the bottom), so the closer the oil level is to full, the faster it fills. Therefore, add oil slowly and in small amounts, and do not attempt to “top off.” Do not allow the oil level to surpass the upper portion of the crosshatch pattern. Doing so may result in aeration of the oil, reducing lubricity and oil pressure, and may cause eventual engine damage.

I believe you may have just over filled. Do not over look fuel added to oil. I don't think this is the case for you because the issue just happened after you changed the oil. Use this first oil change as a experience for the future.

 

[Rocky Lou]

Thanks Brian, that is exactly what I'm finding with quite a lot on the topic of 'gas in Yamaha outboard oil' such as:

we WANT the oil to be about half way up the stick.
we DO NOT want it at the top of the stick.
I get them in all the time overfilled due to folks not knowing how to PROPERLY check the oil and WONT read an owners manual.
to properly check the oil.
warm the engine up.
tilt motor at least 1/2 way up,clear the trim pins.
wait about 5 min.
trim engine to level,NOT all the way down.
remove the dipstick.
wipe it off.
insert the dipstick fully and remove.

two main ways we get fuel in the oil on the F250 is overpropped and running to cold.

that motor must be able to turn 5800 RPM with the days load, not yesterdays load.

Also:
The "making oil" (fuel dilution really) is a known issue. Things that contribute to it are piston rings not being seated, thermostat(s) stuck open, too much propeller pitch, operating in very cold water, idling for long periods of time, etc. Yams run very, very rich based on my tests of three different models.

However, many, many Yam four stroke owners who started tilting their motors up before checking the oil level and/or draining their oil, and who only filled to the mid point of the oil level scale, miraculously were pleased to discover that their making oil issue disappeared.

I believe that it is common to all four stroke outboard motors.

Why? Because it is all too easy for oil to be left inside the motor itself, and if this is not taken into account of, then if and when adding oil to the full mark there will be too much oil in the engine.

An automobile engine is configured so that the pistons run straight up and down or up and down at a slant. Any oil that is on the back side of the piston will drain into the oil pan when the motor is stopped. Any oil that is on the vertical webs that support the crankshaft will run into the oil pan when the motor is stopped.

An outboard motor has the crankshaft positioned vertically. The webs that hold the crankshaft are horizontal (act like shelves) and the pistons are moving horizontally. If an outboard motor is left trimmed in then oil collects behind the pistons and on the horizontal shelves that comprise the webs. Say someone checks the oil. It appears low. He adds oil to get it to the top of the dipstick scale. There is now too much oil in the engine.

So, the procedure is to tilt the motor up to force the oil to run back to the pan. Then, just to be on the safe side don't try and top off the oil. Just get it somewhere in the middle of the dip stick and all will be well.