looking for 2011 yz450f engine oiling diagram

In a nutshell i sucked enough sand through my crankcase breather at coos bay last weekend that i noticed it in the oil filter. After pulling the valve cover its coating the tract below the breather tube that goes down into the crankcase. Im just trying to figure out where the sand will go if i try to flush it through with oil. And if i can trust the oil filter to catch the remenant sand before it reaches anything important. And ifbthe oil pump is likely to suck it up a and S The bed.Still runs good i havent started it since condition was found.


Edited by NW Briff

The complete oiling diagram can be found in the manual, which can be downloaded for free at these two Yamaha web sites:






When sand or whatever gets into the crankcase and starts to follow the oil path, The first place it goes is up through the pickup screen, through the return side of the oil pump, out through a passage in the ignition magneto cover and up to the internal oil tank at a point just above the sight glass.  If it's in the filter, that means that it went from the "tank" to the feed side of the oil pump, then into the right crankcase cover at the low pressure check valve and up into the filter well.  From there,  the oil passages run back into the cover and branch two ways.  One leads to the crankshaft oiling seal and into the crank to feed the rod bearing, and the other runs under the back of the cylinder to feed the top end (by running up around the right rear cylinder head bolt to the head), the chain tensioner (via the left rear head bolt) and over to the left end of the transmission shafts to feed them.


The biggest problem would be trying to get whatever sand still exists in the oil tank area out.  The picture here is an '06, a Gen2 engine.  Yours is a Gen3, so the picture isn't exactly what yours looks like, but it's a similar situation.  You can see how much baffling there is at the bottom third of the tank to keep oil from sloshing away from the passage out to the pump.  This is made more difficult by the fact that there is no really direct access to the oil tank to flush it.


What you might try is to disconnect the pressure balance hose at the right side cover and attach a funnel or a squirt bottle and run solvent (perhaps with 30% ATF added) down the hose and out the drain plug under the water pump.  At some point, you could also fill the tank with 1/3 to 1/2 quart of the solvent and pump air at about 25 psi into the drain plug to agitate things a bit and then flush some more.  Both oil pumps should be thoroughly inspected, too.  They are accessible by removing the clutch. 






Thanks for the quick reply. Had trouble with the download but i need to get a paper copy anyway.

I did not see any evidence of an external oil line on my bike. After seeing the pics you posted im almost thinking flushing it would be near impossible.

Upon closer inspection i found sand inside the camshaft bores and in the cutouts on the gears. Intake valves appear to have loosened up out of spec somehow? I would expect them to be tight. Exhaust valves are dead on. Adjusted 45 hrs ago. I have to find the paper to double check what i set them to last.

Pretty tempted to just tear it down.

Edited by NW Briff

I think your correct on teardown. Catastrophic engine failure is way worse if you find it could have been avoided or at least minimized.

I did not see any evidence of an external oil line on my bike. 


Sorry about that little slip. The external pressure balance hose was eliminated on the '10 model.  And that means the only way into the oil tank to fill from the top would be to remove the flywheel cover and use the return oil passage.  Doesn't look like it would be very effective, does it?

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