questions on 07 wr450 f

hi i have just changed to a 12/07 wr450 f and im wondering if the engine and gearbox are seperate to each other. I went for my first ride on the road yesterday. when i got home the engine was noisier then when i left. i did check engine oil that was fine but i wasnt sure if the gearbox was using the same oil as enine?? I have changed over from a 2stroke so im still not sure about the 4 stroke. i have tried to get a manual on the wr 450 f from the links in thumper talk. the manuals that i have downloaded are wr450fw and wr 450 f x im jus wondering what the difference is apart from these being off road only. would any 1 know where i could get the right manual? or where the oil checker is in the gearbox?? Cheers if any1 can help

Edited by myk 777

Engine and gearbox share the same oil in that bike.

ok thanks. so id check the oil from the dipstick front of engine and fill from the left hand side where the filler cap is. i know this is a stupid question but would have been much better if i got a manual with the bike.

Yes. Also from what I remember the manual states to run the engine for a little bit before checking oil for it to be accurate. Has to do with the dry sump I believe.

Get a SERVICE manual and read it.

This is a high maintenance bike compared to a two stroke; don't guess.

Edited by Krannie

You can download a PDF version of the manual from either of these two sites:

Many of the manuals on the Euro site (first link) can be printed, but none of the ones from the Aussie site can. They are all also tri or quadralingual. OTOH, they're free and readily available.

The bike is a dry sump lube system, wherein the oil is kept separated from the engine itself until it's pumped to the lube points through the system. As it drains back to the crankcase sump, it's picked up by a second faster pump and returned to the storage volume, so the sump stays "dry" in operation. More info here:

Meanwhile, here's a summary of the oil change procedure (for a YZ450, it's the same as yours):

A common failing of engine oils used in motorcycles that share their engine oil with the transmission is loss of viscosity through shear forces applied by the transmission. The additives that make a multi-grade oil like a 10w-40 able to behave like the heavier grade when hot can be easily and very quickly destroyed by use in a transmission if they are not the more expensive, stronger ones used in multi-grade gear oils. There is a surprising number of otherwise excellent engine oils that will suffer from this shortcoming because the blenders of the product didn't intend for them to be used for bikes, and didn't spend the money on the more costly additives. Even some commercial grade (read "diesel" or "truck") oils will collapse under such use. The number of motorcycle specific and C grade oils that fail this way is diminishing, but weaker ones do still exist, and the evidence of the viscosity loss is undetectable without test equipment. If you are running such an oil, that could explain some of the additional noise you heard when the engine was hot.

To avoid the problem, use an oil that you know works from lab tests, trusted recommendations, or your own experience with testing samples of your own used oil. You'll be more likely to catch a good one if you use premium quality motorcycle specific oils or top grade commercial oils. Refer to the manual itself for other recommendations.

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