::..never got a real answer to this question..so..::

[hANNAbONE]

The dry sump in our Supa10's do not allow for increased pressures in the motor.
Oil is pressure squirted onto parts when the mill is operated.

So, if I overfill the oil reserve tank, or underfill it for that matter, how will it affect the motor?

What am I not understanding here.?

What would be the reason to not throw 4 quarts of new oil in the tank and call it good?

Why all the measuring and such???

 

[macca]

Is it a dry sump? Oil sight glass in the crankcase would indicate not? Plus it doesn't have a separate oil tank or oil in frame
Just a thought.

 

[Waspworks]

Is it a dry sump? Oil sight glass in the crankcase would indicate not? Plus it doesn't have a separate oil tank or oil in frame
Just a thought.

It is a dry sump...
Oil is carried in a separate oil tank (that just happens to be) in the sump.

Greg.

 

[Koinz]

The dry sump in our Supa10's do not allow for increased pressures in the motor.
Oil is pressure squirted onto parts when the mill is operated.

So, if I overfill the oil reserve tank, or underfill it for that matter, how will it affect the motor?

What am I not understanding here.?

What would be the reason to not throw 4 quarts of new oil in the tank and call it good?
Why all the measuring and such???

I'm speculating here, but I suspect the tank has a certain capacity as well and you probably want to leave some space for expansion of oil in the tank. So, I would think yamaha provides fill levels for a reason. I don't know if a 1/4 of a quart will make a difference though.

 

[PVC]

I'm speculating here, but I suspect the tank has a certain capacity as well and you probably want to leave some space for expansion of oil in the tank. So, I would think yamaha provides fill levels for a reason. I don't know if a 1/4 of a quart will make a difference though.

::026::

 

[SisuTen]

The dry sump in our Supa10's do not allow for increased pressures in the motor.
Oil is pressure squirted onto parts when the mill is operated.

So, if I overfill the oil reserve tank, or underfill it for that matter, how will it affect the motor?

What am I not understanding here.?

What would be the reason to not throw 4 quarts of new oil in the tank and call it good?

Why all the measuring and such???

Not sure what you're referring to regarding "measuring and such".

Paul

 

[Yamaguy55]

The purpose of the separate "oil tank" within the engine casting is to reduce engine depth. The older SR500 and the current DRZ400 have the frame itself as the oil tank. No matter where you put the oil, wet sump, dry sump, etc, it is fairly standard that you do not overfill four stroke engines. Part of this is windage, or the excess oil being swept up with the rotating items and not only causing drag like running through waist deep water, but also making the oil into a froth, which doesn't lubricate well at all. Oil pumps are designed to pump liquids, not foam. Yes, modern oils contain anti-foaming agents, but nothing can overcome any amount of foaming.

The old TX750 Yamaha of the early seventies had this problem, and it would cause catastrophic engine failures. That was a design flaw in that model with the balancer shaft submerged in the sump. (for you history buffs: that was Yamaha's first use of the balancer idea) and poor oiling passageway designs. We don't have those problems, I doubt anyone has had legitimate oiling failures with modern bikes. That doesn't mean we should press our luck and blow off the design engineers recommendations.

Bottom line: when you properly change your oil, fill it as stated in the manual as to quantity. At that point, you'll see the oil, when cool, at the lower part of the window after starting, but shut off before warming up. After it warms up, it will look very full to slightly over full. Since you get that much additional volume just from the oil warming up, it wouldn't be prudent to dump in another .25 quart/.23 liter and hope for the best.

At least I won't, with mine.

 

[SisuTen]

The dry sump in our Supa10's do not allow for increased pressures in the motor.
Oil is pressure squirted onto parts when the mill is operated.

So, if I overfill the oil reserve tank, or underfill it for that matter, how will it affect the motor?

What am I not understanding here.?

What would be the reason to not throw 4 quarts of new oil in the tank and call it good?

Why all the measuring and such???

This isn't about the section in the service manual that tells you to put in part of the oil, start the motor and then add the rest, is it?

That's for the initial start after an engine is disassembled and rebuilt.

The refill capacity with a filter is 3.59 qt, not 4 qt.

 

[Tremor38]

The purpose of the separate "oil tank" within the engine casting is to reduce engine depth. The older SR500 and the current DRZ400 have the frame itself as the oil tank. No matter where you put the oil, wet sump, dry sump, etc, it is fairly standard that you do not overfill four stroke engines. Part of this is windage, or the excess oil being swept up with the rotating items and not only causing drag like running through waist deep water, but also making the oil into a froth, which doesn't lubricate well at all. Oil pumps are designed to pump liquids, not foam. Yes, modern oils contain anti-foaming agents, but nothing can overcome any amount of foaming.

The old TX750 Yamaha of the early seventies had this problem, and it would cause catastrophic engine failures. That was a design flaw in that model with the balancer shaft submerged in the sump. (for you history buffs: that was Yamaha's first use of the balancer idea) and poor oiling passageway designs. We don't have those problems, I doubt anyone has had legitimate oiling failures with modern bikes. That doesn't mean we should press our luck and blow off the design engineers recommendations.

Bottom line: when you properly change your oil, fill it as stated in the manual as to quantity. At that point, you'll see the oil, when cool, at the lower part of the window after starting, but shut off before warming up. After it warms up, it will look very full to slightly over full. Since you get that much additional volume just from the oil warming up, it wouldn't be prudent to dump in another .25 quart/.23 liter and hope for the best.

At least I won't, with mine.

Just to add a tiny bit to that... One of the reasons you don't fill an oil tank in a dry sump system completely full is because you want allow foaming space at the top of the tank...which reduces any airation of the oil.