Too much oil?

[ddaniels]

Generally speaking, and I have no idea if different types of bikes would yield different results, what negative consequences would there be to putting too much oil in the crankcase?

 

[Tom R]

Your crankshaft will whip it into a froth....

 

[Nessism]

Depends on how much extra. A little bit won't matter but too much may purge out the crankcase breather and spill onto your rear wheel (worst case.)

 

[ddaniels]

Could it result in burning some of it out the muffler?

 

[Cipher]

if the crank is submerged power loss. think its called windage.

 

[Nessism]

Could it result in burning some of it out the muffler?

I don't think so. The sump is separate from the crank area so I don't think there will be extra windage or spraying of oil film on the cylinder from the underside unless there is quite a bit of extra oil.

 

[Steve]

Some of that froth might be drawn off the top, through the breather. That would make it back to the airbox, then through the carbs, resulting in a bit of oily smoke.

.

 

[Nessism]

Some of that froth might be drawn off the top, through the breather. That would make it back to the airbox, then through the carbs, resulting in a bit of oily smoke.

.

Good point!

 

[Steve]

Every once in a while I get lucky.

.

 

[ddaniels]

I drained some off until I could see the top in the window. Only drained off about half a pint.

 

[alke46]

Is this just purely a myth or can it cause a gasket to start leaking?

 

[Grimly]

Is this just purely a myth or can it cause a gasket to start leaking?

The oil is getting flung around in all directions internally, so normally the gaskets are designed to cope with this.
If the breather is partially blocked, and the crankcase pressure builds up a little, then a weak spot in a gasket or seal may be found.

 

[Sparkie]

Hello, so as not to have to open a new thread about oil, with your permission I take the opportunity to ask here. My bike it's a GSX1100EX and I have to change the oil shortly, the recommended by the manufacturer it's SAE 10W40, but I have a friend who tells me that it?s better for my bike SAE20W50.
What do you think?

 

[Nessism]

Hello, so as not to have to open a new thread about oil, with your permission I take the opportunity to ask here. My bike it's a GSX1100EX and I have to change the oil shortly, the recommended by the manufacturer it's SAE 10W40, but I have a friend who tells me that it?s better for my bike SAE20W50.
What do you think?

10W-40 is the best compromise for all riding conditions. 20W-50 would be good for riding in high temps but oil delivery will be slowed at cold startup.

 

[Sparkie]

Thanks for your quick answer Nessism.

 

[ddaniels]

I and just about every Yamaha FZ1 Gen 1 owner overfill the oil to the top of the site glass. The mfr line is 2/3 up the site glass.

Owners do this so the overly sensitive oil warning light doesn't light up the dash. I have on occasion over filled as much as D.Daniels (1/2 pint) beyond the top of the site glass with no harm or perceived loss of performance. Corrected by quick drain of the 1/2 pint.

The problem with filling to the top of the site glass is it means you have to juggle the bike back and forth some times to see the top of the oil. The other thing that I've experienced is that the Gen 1s show one level oil level when cold and a higher level when warm. Owners need to set up a routine to check the oil at the same time, same center stand or not, and temp to avoid over filling. Never noticed whipped or frothy oil, but I only have 260K on it, so far

Good info isleoman, thanks.