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What YZ engines fit different years?

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Hey guys,

I recently bought a brand-new 1996 WR 250. This bike absolutely rocks, great off-road suspension (the best I've ever had bone stock) strong engine and good handling. They don't make 'em like this anymore...period.

So...I live in californica, and you can't plate off-road bikes anymore, and I want to make this bike street legal so I can get from point A to B legally.

I understand the WR engines are based on the 94 YZ so the question is this;

What YZ frames will a 94 engine bolt into? Did they keep the bolt-up/swingarm geometry on later engine designs? I need this info to go fishing on craigslist for a previously plated YZ or WR that I can swap all my new stuff onto.

Thanks in advance..

Tom

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If I were a betting man, I'd say the motor would fit any YZ250 frame from 1993 to 2010. The one known glitch will be at the engine/swingarm pivot mount. The later bikes (2002?) use a bigger pivot shaft, so you need to replace or modify the bushings that fit into the cases. TT member BRM has been down this road.

Good luck!

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CaptDan,

Thanks for the info!

Re: wr250 - I got the bike via craigslist. I watch it all the time for bike deals...finally hit pay dirt, a fellow bought the bike back in 98 new from a dealer and stored it. His wife told him to get rid of it and so ....

Had to break it in, set the suspension, jet it, etc. This bike is probably the best off-road bike I've ever owned and I've had many later models, WR 426, YZ 250F, CRF250X and lots of smokers before that mostly off-road modded KX's and KDX's. The stock tires are Bridgestone Gritty - LOL. They still work pretty well for 14 years old...LOL... I can't find fault with it, I read somewhere the tanks on WR's are rough on the nads, but the '06 is right on design-wise. The 02 WR426 I had came with a tank that did bust your nads, so the design went backwards there, same with the suspension...although I think all that extra 4-strk weight is tough to deal with...this bike makes the newer WR 426 I had (with YZ cam and pipe) feel like a toad in comparison, and the fun factor difference is huge. The only downside is the wheelspin, and that isn't so bad as I relearn throttle control.

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If I were a betting man, I'd say the motor would fit any YZ250 frame from 1993 to 2010. The one known glitch will be at the engine/swingarm pivot mount. The later bikes (2002?) use a bigger pivot shaft, so you need to replace or modify the bushings that fit into the cases. TT member BRM has been down this road.

Good luck!

You could go a earlier since I beleive the 88-96 yz uses the same casting for the main cases : 2vm prefix on the part # and that bushing in the cases for the swingarm although very tight can be removed with some heat and persuasion and was at one time an available part ( figured that out trying to shoehorn a yz465 engine into a 2001yz426 frame)

I love the 94 -97 wr250 probably my favorite bike of the different ones I owned ...... a flywheel wieght, Eric Gorr's performance handbook and a little epoxy in the right spot can transform the midrange monster of a motor into a kdx200 on steroids feel

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So wait, you're saying there is a good chance I could easily adapt my 92 motor into a modern rolling chassis? Tell me more! : )

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Here's some pictures of the beast:

newwr2.jpeg

newwr1.jpeg

I've ridden it every week since I got it, it had about 10 hours on it when I took these pictures.

The guy I bought it from installed renthal bars, a carbon-fiber case guard, an answer spark/arrestor muffler (it came with 2 to be exact - both brand new), the Malcolm-Smith fender mount tool kit, radiator braces, and frame guards. I paid 2500 for it and I can't believe my good luck - mebbe good Karma, I sure lost my butt on the last 3 bikes I sold...LOL...so mebbe it evened out some.

Engine hits are a personal preference thing I guess, but I like bikes with big mid-range strength, I had a slightly modified 89 KX250 that had a similar feeling engine, and I did pretty well on it play riding and racing CC.

Edited by SPUTTER
more info

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Beautiful bike! The chassis was not bad on that bike, but the tank was horrible. A yz tank and seat from that era will make a huge difference. It would also protect the pristine parts you have.

But yes, you cna swap that engine into virtually any yz you want. Even though the 2002-2010 engine is totally different, it still uses the same mounting points. Granted, you'll need to deal the different Swingarm Pivot size, but the engine swap is do-able.

Before you do anythign, check the green sticker laws. I believe they use the VIN number to determine legality. This means you could remove the engine from a 2010 and use a bicycle crank and pedals for power, but it would still be red only.

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Man that bike is awesome! So cool that you can still find something like this in 2010. You lucked out for sure......I would go buy a lotto ticket if I was you haha. That seat/ tank combo looks the exact same as the 98-02 WRs....so not sure how they went backwards there.

With some good ideas, good fabrication and a welder you can pretty much put any engine in any frame. So this should be a relatively easy swap.

I have no idea how you are going to make this bike street legal. The only way is to have a good friend that is a sherrif

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I'm hoping to find an already licensed bike and just use the frame. The VIN is on the frames and here in CA those already street legal prior to 2003 are grandfathered in. Right now, for example, even in my area, there are a couple of street legal pre-2003 WR400's and 426's for sale. Finding a 2 stroke street legal for cheap is tough though, but it's no big deal to keep an eye out for one.

Rcannon - I have to disagree with you on the tank - I had an 02 WR that was tough on the nads, but this bike isn't. Something else ergo-wise had changed. I'm an advanced rider who moves around a lot on a bike, and I've had no problems whatsoever. As a comparison, I hated the ergos on my 03 YZ250F... yes, narrow seat and chassis, but just not right for me...maybe cause I've spent a few decades riding wider chassis bikes and have grown into them...wider seats are cool too, IMO. I'm an off-road rider, not an MX'r. Look at all the guys who get aftermarket foams and such for the newer bikes -

I'm pleased as punch that I bought a bike that I don't have to buy a large tank for, a softer seat, revalve the suspension (I do that myself, but it's a drag)... and so on.

If General Lee had this machine, we'd of won the war! LOL....

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On 7/4/2010 at 10:10 AM, Kurlon said:

So wait, you're saying there is a good chance I could easily adapt my 92 motor into a modern rolling chassis? Tell me more! : )

Look ive got a wr250 92 model tryed switching motorover to my 97 model frame yeah all sweet till i noticed that the bloody expansion chambers are a total different setup so ull have to modify the pipe to fit champ look ive got shitloads of projects happening bu t yeah my yz's seem to be my problem bikes as ll the cr's are sweet but not the yz's are pain in the ass but yeah still my babys!!hahah

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