Oil changes

[Sasquatch]

I think that a few people do not grasp the meaning of Dry Sump motor! A dry sump motor does not carry all its oil in a pan under the engine like your car or truck. It carry's it in a remote tank.

Unlike a car or truck there is a scavenger pump in the bottom of the motor that pumps the oil to the tank. The scavenger pump is a low pressure pump that will pump oil even foamy oil back to the tank. Oil gets a lot of air mixed with it as it is flailed around by the crankshaft upon exiting the cranks bearings.

The tank on a dry sump system works like that oil pan on your car or truck. It allowes the air and oil to seperate and sucks air bubble free oil from the bottom of each to the high pressure pump that feeds the bearings and anything else in the motor that needs a bit of oil. That is why you should not let your oil level get extreemly low because then the high pressure pump will start pumping air bubbles that have not seperated from the oil yet. Air is not a lubricant and is bad for bearings and stuff.

So to be clear you must put oil in the tank its where the high pressure pump that feeds your bearings gets its oil from. You can put a bit in the motor if you must but it is poinless as it will just be pumped back to the tank. Yamaha recomends adding oil to the motor after an engine rebuild and if you look at the volumes of oil changes with and without oil filter change then the one for after rebuild you see that there is a lot of oil still in the motor that we do not drain out.

Adding oil to the motor does nothing to feed your bearings, you are not starting the motor up dry if you add no oil to it. Adding all your oil to the motor does start your motor up dry because now the motor has to wait for the oil to be pumped from the motor to the tank so it can be pumped to the bearings that need the oil. Warm oil in warm garage won't take long but if done in a cold garage time would be much longer.

The main reason I always point out the fact that you do not need to add oil to the motor is becuase I always hear of people filling the motor and not the tank. It stops confusion and people filling the motor with oil. Now having three quarts or liters of oil dragging and then fllailing around in the motor around the crankshaft is not what the manufature had in mind for stress on both the crank shaft and engine seals never mind that the high pressure pump now has to wait for its life retaining liquid gold.

So again if it makes you feel all warm and fuzzy to add a little oil to the motor then go for it no harm done but for sake of your motor add some to the tank and never rev the motor up after an oil change. Always let it idle for a few minutes while checking for leaks and engine faults or strange noises (if any shut down immediatly). Then shut down and check the oil level in tank. If oil level is abnormaly high or low or you found a leak or heard strange noises, there is a reason that needs to be addressed before you start it again.

I usually put in about 2 and a half liters in the tank none in the motor run and then top up to about the middle of the high low range. I find that after I take it for a ride and check it when totaly warmed up it is usually right up to the full mark or real close to it. I reason that till the motor is warmed up the way only a ride can warm up a motor that there is still a few onces or mililiters of oil stuck to various components in the engine that has not made it back to the tank. This is why I always check my oil after a ride.

Just trying to help by clearing up confusion!

 

[Dimebag]

Great write up Sasquatch

 

[Irv]

Great write up Sasquatch

X2, and exactly what I have read on here before, no need to add oil through the top engine plug.

Thanks Sasquatch

 

[YAMAMISSILE]

Great info! I didn't know this. Makes perfect sense.

 

[17Rambler]

I can't read the first post......that creepy guy on the left scares me.

 

[Sled Dog]

I can't read the first post......that creepy guy on the left scares me.

Wait till you see him sweet talk a cow moose!!!

 

[Paraclete]

<<<<< Thisone is more freindly

 

[snobill]

Didn't know that either thanks

 

[Tessie11]

If your oil tank was over-filled what is the impact? Would you see additional oil in the air-box?

 

[Sled Dog]

If your oil tank was over-filled what is the impact? Would you see additional oil in the air-box?

Well if the extra oil is pumped back to the tank and then pumped back into the engine I would say none because the engine would only get and hold so much oil. I actually thought the oil flowed back to the tank with gravity and was picked up and pumped through the engine. If it was that way if the oil can held too much oil some oil would stay in the bottom of the engine and you would lose the benefits of not having a sumpless system as the crank plows through the oil in the bottom of the engine.

 

[Sasquatch]

If your oil tank was over-filled what is the impact? Would you see additional oil in the air-box?

If over filling caused more oil to stay in the motor yes you could see additional oil in the airbox because of more oil being whipped up into oil mist and going out the breather line.

Something I learned and was talked about on here when I bought my 05 was that if you over filled the tank it would not take to long and the level would drop. I was checking my oil in the morning after running the sled till the light went out and pulling out of the garage. Lift the hood check the oil. Stick would show it was down a little so I would fill it back up to the mark. After a while of this I thought I had an oil burner because I had gone through a liter (quart) of oil in a few rides. Talking about it on TY some others said the same thing.

Then one ride I checked the oil a few miles out on the lake while waiting for some others to show up where we meet up in the morning. I was over full by 3/8ths of an inch or so. Weird! I'd checked it in the morning and added till full. Hmmm I must have over filled it I thought. So when I got back that night after a 200 miles ride I checked it again and it was close to the fill line. I was also finding lots of oil in the airbox and wondered why!

So next ride I knew the oil level was at the full because I had checked it after my last ride. I checked it later in the day and it was still around the full line and at the end of my ride it was still full. Next ride I warmed the sled up till light went out moved it out of the garage and checked the oil level and it was below the mark. Really weird! So rather then add any I just rode it figuring that it was between the line so no harm would be done and I wanted to check it again down the trail. When I did it was full again.

So I started checking the oil after a ride from that point on and it used 300ml in 2,500 miles at the rate I was using oil before that it had used a liter in 1000 miles. Talked with Convert and a few others about it here on TY and some others said that they had found the same thing. I came to the conclusion that the oil was winding up in the airbox somehow because I was overfilling it.

When I did notice the oil level drop a bit was after lots of long full throttle runs. Also would find more oil in the airbox. In 06 they redesigned the block and added more baffling to reduce oil mist getting into the airbox by keeping it in the motor.

Take it all with a grain of salt. Your experiance could be different.

 

[Sasquatch]

I can't read the first post......that creepy guy on the left scares me.

What are you saying, my face is creepy?