inking of buying a yz400 f

hi all, first time on this site so hulloo to everyone!

a mate of mine has a Yamaha yz400f, at least I think its a yz 400! did Yamaha make a wr400 in 1999/2000?. the bikes on a "T" plate which here in the uk makes that a 1999/2000 model, so not really sure if its a yz or a wr! its not been started in two years ,other than that it looks ok for its age, he's wanting £700 for it

whaddya think?




For those years it could be either a YZ400F or a WR400F. The WR should have lights while the YZ shouldn't. I believe the WR has a steel subframe while the YZ has an aluminum one (some people take lights off the WRs to save weight, and others put them on YZs to ride on the street). The WR should have a kickstand while the YZ shouldn't. 


I don't know what prices are like there vs here, but google tells me that's around $1000 USD. That sounds high to me for a bike that's been sitting for a couple years, especially as something may have happened to cause it to sit. If you know him well and trust that it really did run well when parked, I'd expect to need to clean the carb well (maybe some new parts too) and do fork seals, at a minimum, plus fluids, plus check the valves. If you don't know him well enough, I'd be prepared for an engine rebuild (it's possible that it was parked because it had problems, the most likely being valves).

You should inspect the cam chain before running the bike, too, just in case it's stiffened up.  One link is all it takes.  It gets on the wrong place on the chain at the wrong time, timing skips, valves bend, ...disaster.

that's great information, many thanks for that, I now think its a wr not a yz because of the lights/steel frame and sidestand, that's one problem outa the way!

it does sound like a bunch of work to get it running again, im ok with engine rebuilds, done a few now , had a ttr that I rebuilt but would rather avoid it if possible! I,m assuming it has bucket shims for valve clearences?, so far I'm not committed to it, i'll see if he can get it to run before I do anything else

again thanks for your help, most valuable



I'd say if it starts and runs it's a decent buy. The WR and YZ 400 bikes have a great reputation for being solid engines. But if they do need a rebuild then they will be as expensive as any other bike. The carburetor is also getting old and will probably need to be tuned up. This can be easy or it can open up a bag of worms due to the age and gaskets getting dried out etc. You can get carb rebuild kits for around 50 USD.

Also remember that these were the first of the modern 4 stroke MX engines. There were a lot of advancements made in the few short years following. If you can afford to get something 2003 and up it would be nice.

The WR and YZ of the era both had steel main frames. I imagine there are some differences, but I'm not sure I could tell other than kickstand lug.


Yes, they are shim under bucket. 

hi guys , thanks for all your replies, that's been very helpful, one further question if I may, the bike in question does not have a ignition or key, is that how they came from the factory? I assume that the yz being a mx bike wouldn't need one but I would have thought the wr should have one?

thanks again for all your replies


Nope, no key switch.

Even the later electric start WRs don't have keys, just a rocker switch. YZs have a kill button and that's it, I suspect WRs are the same. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now