Help - general maintenance........OIL

I changed my oil & filter over the weekend. The oil I drained pretty much filled half of a gallon jug as normal. After I replaced the filter I filled it back up. I didn't even get a full quart in & it overfilled & ran down the frame. After cleaning everything up, I ran it up & down the road figuring the oil would get sucked wherever it needed to be. When I checked, it was still full.

I'm not the smartest duck on the pond but I know this thing takes twice as much oil as I was able to put in. Any ideas?

Is it possible that you did not drain the oil from the frame? I did this once on my 400, drained all the oil from the case but forgot to drain it from the frame so when I tried to refill it overflowed. Be careful about running the motor it is most likely low on oil.

I've always drained from the crank only and have been fine. Wouldn't the oil in the frame move down?

I'll drain it again from both drain plugs & try again.


I thought the same thing when I had to drain the oil from my 03 WR450 to have it shipped to PR. I opened the dipstick in the frame and drained the oil from the case. I left the plug out for about an hour to make sure it all got out. I put the plug and dipstick back in and had it shipped. When it arrived I filled it with the correct amount of oil (as per manual) and started it up. I removed the dipstick and oil gushed out of the top of the frame. I pulled the drain plug and removed the oil in the motor to see how much there was in it. I got about as much oil out of the cases as I had just put in. I then removed the frame plug and got just as much oil out of the frame as I did out of the cases. I don't know why but the oil aparrently didn't run out fo the frame to the cases. I checked the screen in the bottom of the frame where the hoses connect and it was not clogged. I then put all of the plugs and hoses back on and filled it with the correct amount of oil, started it and checked the level again. It's ok now.

So, I just learned that there is no shortcut to draining the oil from these bikes. Follow the manual and it'll be fine, don't and you get a mess.

I do the frame oil drain bolt and the drain pan main bolt and it empties out every time and it takes 1.2 liters to get it back to full. I do the filter only ever third oil change. I change the oil after every weekend of riding. :)

If the oil from the tank was allowed to drain to the sump, it would be a wet sump engine instead of a dry sump engine.

From memory, there is a ball valve that prevents the tank oil draining into the sump.I drain the tank by removing the pipe that goes from the frame to the bottom of the inner clutch cover(remove it at the bottom). This ensures that you get as much of the old oil out as possible.

This is how the YZ/Wr oil system works. There are 2 oil pumps. The scavenge pump collects oil from the bottom of the sump and returns it to the tank. The main oil pump collects oil from the tank and pumps it to the engines oil galleries. All things working well, when you drain the sump you should only get about 300ml of oil. If you get a lot more than that from the sump the scavange pump isn't working correctly.

hope this helps,


As Indy points out, you normally need to drain both. BUT, if you don't warm up the engine before draining it, there won't be much oil in the frame sump.

The WR's use a dry sump design. However, oil has to pumped up to the frame sump from the engine case. There is only one oil pump - not two. This is why you have to warm the engine up before you can check the oil level as it won't even register on the dipstick if you don't - it's down in the case. BTW, you should always add oil to the engine case - not the frame sump.

Here's the procedure I use and it works every time:

1) Run the engine long enough to warm it up. This is primarily because warm oil drains easier and more thoroughly than cold oil, and it helps to get a lot of the combustion contaminants out more effectively.

2) Now the frame sump and engine case will both have oil in them. Drain them both thoroughly.

3) Inspect the copper washers and replace if needed - they don't last forever. Reinstall and retorque the drain bolts

4) Fill with recommended amount of oil depending on whether or not you are changing the filter.

5) Start the engine and let it run for the minimum specified time in the manual - this is to ensure that the oil measurement in the frame sump will be reasonably accurate. It's not a bad idea to check the oil pressure while the engine is idling too.

6) Check the oil level and adjust as needed by adding oil to the engine case only. Restart, idle, recheck until you get the level where it should be. It's usually fine on the first check.

As I said, this method works perfectly for me. :)

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