Yamaha 90 hp 2 stroke oil levels

[dnej]

Any one with a 90 hp Yamaha,2 stroke, ever checked the operation of the oil level indicators on the instrument gauge.

There are three indicators, on the gauge,and as the oil level comes down , so the indicators are supposed to " empty out" and go to the next rectangle.

How the heck does the level indicator on the bottle work, so it passes the message to the gauge.

The indicator in the bottle is not a float as such, and is way down near the bottom of the bottle, yet it shows the levels from about 2/3 up the bottle.
Clear as mud?
David

[ranmar850]

I had one up till recently, didn't trust the gauge for that reason. just check the level visually, it's going to use about a litre for every 50 litres of fuel, so make sure to check it every 150 litres? It'll certainly let you know hen it is getting low.

[dnej]

I drained the oil to a lower level, and it didn't seem to make any difference. ( I always check it by visual in any case).
David

[gazza2006au]

Yamaha's portables are 100:1 i dont know if the medium to large HP range are variable oil injection i guess they would be? so it would vary a lot more than 100:1 ratio at say idle to flat stick

do u have a oil bottle on the engine as well as a tank inside the boat? my mates own a 2004, 115hp Yamaha they have the two bottles, once the bottle on the engine runs low it automatically tops up the bottle from the main tank inside the boat and if none is available the oil alarm alerts the driver. pretty nifty idea compared to the old oil jug measuring days lol ;D

[ranmar850]

On extended trips, it seemed to average out to 50:1. if we had 300 litres of fuel with us, we needed at least 6 litres of oil. Only had the engine mounted tank, I think the 115 up had the remote tank, from what I have seen.

[dnej]

Well, I got down to the nitty gritty of the diagrams in the owners manual. I measured the reservoir, which is in the shape of a capital L, and calculated the volume, in cubic cm, and associated litres.

The float is located on the lower part of the reservoir , on the lower part of the L. and the float in the bottle is magnetic, and works like a float on your brake fluid in your car.

However, you need to use around 2 litres of the 3.3 litres, bringing the oil level down to the head of the float level. Then it starts to operate from there.
Now that makes sense.
The diagrams shows the float indicating levels above where it is mounted, and that is not possible..No wonder I didn't think it was working.
So now you know what I know.
David

[Crunchy]

And did the alarm work? With oil level low tilt motor up and turn on ignition, should be a loud audible alarm.

[dnej]

Crunchy,
Going to do that today. I wonder how many of these models have owners that just think the reeds don't work. The diagram is completely incorrect.

Funny though, I found another diagram on another random page, showing a squat tank, with the float sender on the top of the bottle . That makes sense. I wonder if there was a smaller bottle originally.

David

[Crunchy]

I've never seen the little indicator bars on the gauge go down but did get an alarm once when I trimmed the motor a long way up so good to know the alarm works, but I have a pre-trip check list and checking oil is up near the top of the list just after "insert bungs" :-X, I always carry a few lites of oil in the boat but never had to use it on the run but have given it away to other boaties who have run low or forgotten to check!

[dnej]

Crunchy, I am the same.

The bottle is always full of oil, because I top it up like you.

In regards to the indicators, they wont move until the lower section drops the level below the top of the float unit. The diagrams in the book show that one is dropped when the level is about one third down the bottle, but that rubbish.

The indicators don't work until after using over 2 litres, which brings you down to the squat area.. Boy did Yamaha argue with me. That's the reason I measured it up. If you read the wording alongside the diagram, you can work out the calculation.
David

[dnej]

Well, did a final check. Took the oil down to about half way the squat end of the bottle, where the float unit is mounted, on the L shape
At that point one reed emptied out.
Reduced the oil level lower again, and the second one emptied out, leaving only one reed.

At that point the last reed started flashing, and the buzzer sounded .As I said previously, the diagrams are incorrect. The level indicator does not work until the oil is below the head of the float indicator . Q.E.D
David