Wide Ratio Gears in '03 or '04 YZ250

[dog2]

Does anyone know if you can install WR450 gears in '03 or '04 YZ250 2-stroke? I know it could be done in the older YZ's, but I haven't heard of anyone doing it on a newer one. I really wish Yamaha bring back the WR250 two stroke to give these KTM's some competition off road.

 

[fuzzy]

AMEN!

 

[fuzzy]

BTW, do a search on "WR gear swap" and you should find some stuff. There was an older thread going over this in great detail. It can be done. The WR gear need narrowed on a lathe, but I think that's about it.

 

[dog2]

I did a search last night and found a thread, but it was related to older 98-2002 bikes. I couldn't find anything on the newer bikes.

 

[Lissa]

The 99 to 04 engines are basically the same. 98 and below are of the older design. Im going to put the WR 5th (only 2 gears needed and no modifications to the gears) in my 02 this winter. I never liked the WR trans in my 97 WR 250 until I geared it down. It was too wide in the tight NJ woods that I ride in. Even geared down it did an ICO indicated 83 mph! I much prefer the close ratio box of the YZs.
Rob not Lissa (I can never remember my password)

 

[KaTooMer]

Seems like there could be a market, albeit a small one, for wide-ratio gear selection on all MX bikes (didn't Kawasaki have that option for the KX500?). Despite the huge growth of KTM's in the off-road world, there's still a lot of Japanese MX'ers on the trails. Maybe there's more to it than I think, but an Eric Gorr type of person, with a lot of knowledge and some decent equipment, could fill a need for the person who can split his/her own cases and swap out gears. Or maybe there's not enough of us out there to make it work....just my thoughts.

 

[Rcannon]

I think a slightly wider ratio would be nice in my 97 YZ. I dont much mind the lower three gears, but it is difficult to tell the difference between 4th and 5th.

 

[Studboy]

Not to mention that for off-road riding first gear is about as tall as a giraffe on my 02 YZ250.

 

[dog2]

I checked the part numbers on the transmission shafts comparing YZ250 and WR426/450. In 2002, the YZ 2-stroke and the WR 4 stroke had the same transmission shafts, so the gears should work. In 2003 and 2004 they are different, so I still don't know if a swap would work in an '03 or '04 bike.

 

[Mike's 2003 YZ250]

Hey fellas. Anyone figure this out?? I would be interested in knowing. Mike :)