HELP - 2007 YZ 450 losing oil!


12 replies to this topic
  • 127

Posted December 12, 2006 - 06:41 AM

#1

Guys I'm freaking out. Here's the deal:

Changed oil Wednesday night after checking valves for the first time (5 rides). Went riding Saturday and Sunday - MX tracks for a total of 3hrs (on the bike riding time).

I washed the bike last night and when I went to drain the oil I only got 100cc to drain out :devil: ... It wasn't burnt and didn't have any metal in it:excuseme:

So I filled it back up with 1 QT - warmed it up and rode it for 2 minutes in the storage facility area where I keep the bike. Drained the oil back out and only got 690cc's back out... :thumbsup:

Where is the oil going? - No oil on the case, or the motor, no oil on my shock, no oil on the floor or in the bed of my truck...?

This is racking my brain!!!

  • never59

Posted December 12, 2006 - 07:29 AM

#2

did you pull the dipstick? Sounds stupid but once you pull the dipstick, with the oil bolts out the oil will start to flow out real quick.

  • 127

Posted December 12, 2006 - 07:33 AM

#3

I went back and pulled out all 5 bolts... I'm going to try it again tonight...

1. Bottom Drain Bolt
2. Side Drain Bolt
3. Oil filter bolt
4. Dip Stick
5. Oil Entry cap

  • yz007f

Posted December 13, 2006 - 05:17 AM

#4

Just a thought I couldn't see it using oil that fast. I would say did you let it cool down before you drained the oil? Maybe there is oil still left in the head give it sometime to leak down. I know my 450 wasnt like this but maybe the 07's are different? Just a guess lol

  • YZ250F_Rider

Posted December 13, 2006 - 01:21 PM

#5

the oil pump picks up the oil from the crankcase and sends it to the oil tank section in the front of the motor before pumping it to the bearings and such.

The oil tank section apparently has a very small drain hole to allow the oil to drain back to the crankcase. I have noticed that the two of our bikes will drain oil at different rates. The blue one drains sort of normal, and the white one drains really slow comparatively. It may be the drain hole in the tank section has a burr or assembly trash partially blocking it causing the oil to flow back into the crankcase so slow.

I would follow the manuals direction of letting the motor run for 3 minutes and then checking the level with the dipstick to see if your using oil drain measuring is not allowing enough drain time. It took forever for the white one to finally stop dribbling out oil.

  • grayracer513

Posted December 13, 2006 - 03:00 PM

#6

No drain hole exists between the two, but with the engine off, oil runs from the reservoir to the crankcases by the same means it always has; past the oil pump rotors and shaft. Also just like in the past, the rate at which it runs from one side to the other will vary somewhat between different bikes for all kinds of reasons, mostly oil type and temp, and the amount of clearance on the pump.

That should not really have a bearing on this situation the way the OP has stated it, since he says he drained both the "tank" and the crankcases, and regardless of whether it was upstairs or down, the same oil should have been in there somewhere.

In draining the reservoir (front left drain plug), be certain that you remove the dip stick, or the tank won't vent and drain right.

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  • 127

Posted December 14, 2006 - 08:52 AM

#7

Thanks for the info and tips guys. I'm going to put in a fresh qrt warm up ride for 5 minutes and come back and check it... I may just drain it all back into the bottle to see where I'm at and keep checking it...

  • YZ250F_Rider

Posted December 14, 2006 - 09:27 AM

#8

No drain hole exists between the two, but with the engine off, oil runs from the reservoir to the crankcases by the same means it always has; past the oil pump rotors and shaft. Also just like in the past, the rate at which it runs from one side to the other will vary somewhat between different bikes for all kinds of reasons, mostly oil type and temp, and the amount of clearance on the pump.

That should not really have a bearing on this situation the way the OP has stated it, since he says he drained both the "tank" and the crankcases, and regardless of whether it was upstairs or down, the same oil should have been in there somewhere.

In draining the reservoir (front left drain plug), be certain that you remove the dip stick, or the tank won't vent and drain right.


interesting. so that is why there are 2 drain bolts, one is for the tank itself? I havent looked inside the newer ones so assumed there were 2 because of a casting wall or something inside the case.

  • grayracer513

Posted December 14, 2006 - 09:48 AM

#9

Yeah, the left front drain plug drains the reservoir, or "oil tank", and the one they cleverly hid right behind the frame tube on the right rear is the one for the crankcases. The feed and return passages are both internal now, but they are still there, and do the same thing as the external lines did. You can see the return passage built into the ignition cover, in fact. The soft vent hose on the right of the engine is the same hose as the one that went from the steering head to the cam cover on the older bikes; it's a pressure balance between the tank and engine.

Additionally, there's an overfill drain on the left rear (page 3-14 of the manual). This works by letting excess oil drain back through the return passage into the sump, and then out the overfill drain. The process is a slow one, though. It can take up to 10-15 minutes, depending on the overfill, oil temp and weight, etc.

Another thing that the manual doesn't say is that it's a good idea to wait about 20-30 seconds after engine shutdown to check the level, since air bubbles in the return line can blow out onto the dip stick and give the wrong read.

  • Dr._400

Posted December 14, 2006 - 10:14 AM

#10

I'm curious about something. If your not draining all the oil because you think or thought it was leaking out somewhere...........


Are you filling the motor back up with excess oil? Ya know what I mean, if there is lots of oil in the tank you can't see and you add more oil won't you blow seals or will it spew out the crankcase breather ??

Just curious.........:thumbsup:

  • grayracer513

Posted December 14, 2006 - 10:53 AM

#11

I have no idea if this is the OP's problem or not, but yes, if a dry sump like a YZF is overfilled to the point that the oil tank cannot hold the whole amount returned to it, then you next get too high a crankcase oil level, which will cause the crank to wind up oil on it and throw it off onto the cylinder wall, overwhelming the rings. It will also interfere with proper drainage from the top end, which will flood the valve seals and put excess oil in the breather.

  • 127

Posted January 04, 2007 - 10:34 AM

#12

well damn i'll be sure not to overfill but it's been 3 rides since I've had that first original scare - I've checked and changed oil every ride...

seems to be holding - I hope I was just being retarted or something and forgot that I had drained the oil...

  • haole

Posted January 04, 2007 - 01:04 PM

#13

Another thing that the manual doesn't say is that it's a good idea to wait about 20-30 seconds after engine shutdown to check the level, since air bubbles in the return line can blow out onto the dip stick and give the wrong read.


Seriously, the first time I changed the oil, it blew a huge bubble of oil out of the dipstick hole. I was like





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