Changing Oil in '02 WR426

Help, I just bought this bike and am changing oil for the first time. Manual says there are three drain bolts - I can only find the one under the frame, and the oil filter drain bolt. Where is the 3rd drain bolt that I need to remove?

Secondly, do I need to do the oil strainer cleaning and put new gaskets on the drain bolts EVERY time I change the oil? I'm going to be changing the oil every 2-3 rides (I'm a noob, so I don't ride her hard).

Finally, once all drained and cleaned, bolt her back up and then pour 1.3 to 1.5 litres into the oil filler place at the top of the frame (just below handlebars), right? Why is the filler in the frame anyway, any reason other than convenience?

Sorry if these are stupid questions, but I'm just trying to learn here... :)

Thanks in advance for help!


I just drop the main one unless i'm changing the filter aswell. If the gaskets and shit aren't rooted don't worry about it. From memory it takes 1.4 litres

There is also a drain plug in the bottom of the motor. I wouldn't worry about the strainer in the frame but there is a filter on the right side behind a small cover. Yes you add the oil through the dip stick hole between the tank and the handlebars. My US model takes 1.4 qts with filter change. I suggest going to this site and downloading the manual.

Thanks guys - so there is a drain plug under the motor? (in addition to drain plug under the transfer case that I access through hole in the bottom of the skid plate)?

Unlike a 2-stroke that uses one fluid for the transmission/clutch and the piston is lubed by the premix (or injector), a thumper uses one oil for both. Run it for 2-3 min, pull the plug on the frame (use something to deflect the oil or you will end up with an well oiled tire) about a qt will come out and then pull the plug accessible through the bash plate. Then pull the filter cover and clean/replace the filter. Button everything back up, refill the oil, run it for 2-3 min and check the level (the motor must be run to get an accurate reading so run it each time you check the oil). Note, never run the motor with the dip stick out or things will get messy, trust me. :busted:

The third bolt is in the frame just above the top of the bash plate.

The reason the the dip stick is in the frame is because the engine is "dry sump". The oil is stored in the frame and pumped around the engine as opposed to a "wet sump" engine where the oil is stored in the bottom of the engine. This reduces the chance of seizing the engine when pulling long wheelies :busted: or doing long hill climbs as in a wet sump engine all the oil ends up sitting in the transmission and not getting to the piston :thumbsdn:.

There is the frame drain bolt, the bolt under the motor through the skid plate, and the filter has its own drain bolt as well (I think its the lower left bolt on the filter housing). I believe those are the three you are referring to.

Great info - thanks guys, I'm off to change the oil now! :)

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