1975 MX250 Forks

[Tahitian_Red]

I have a set of forks from a US 1975 MX250.  I know they are nearly identical to the 74 YZ250 forks and I want to set them up nice.  Any tricks besides Emulators for getting them to work great?

[Davey Crocket]

They bend easy, rotate them 1/2 a turn every few meetings, I run 200mls of 15 weight in each leg and thats that.....no tricks....I have noticed over the years quite often when you pull them apart there are 2 different forks...ie springs and bottom legs different.

[Tahitian_Red]

DC

Thanks for the reply! I'm going to put them on my 75 MX100 (30mm), so bending easy is all relative. 

[Rossvickicampbell]

I agree with DC - I wish I could find a more "robust" set of eligible forks.  I put emulators in them and these made a noticeable difference.

[Tahitian_Red]

On a side note, will any 1974-79 front hub work on these forks?

[Freakshow]

yes all  Yamaha conicals should.  MXA-b, Sc500, YZA-b-c-d, IT - for a long time

I wish I could find a more "robust" set of eligible forks.  I put emulators in them and these made a noticeable difference.

i think you need to look to unrobust yourself ROSS - would be the kinda answer.  Those forks were designed for 70kg riders, anymore and yoru asking them to do a lot more work and specs than they were asked to do, so i reckon there doin prity well for a standard pair of 35yr old 34mm forks. 

[IT400C]

so what diameter are MX250/400B forks anyway?

[Davey Crocket]

34mm

[Rossvickicampbell]

Freaky - such a kind person!  Mate - big boned is natural - can't do much to change that    And I saw 70 kgs once - on the way through!

[IT400C]

so what diameter are MX250/400B forks anyway?

Were they the same as any other Yamaha forks of that era?  i.e. MX360A??

[Freakshow]

yes 34mm tubes.....

[Wendell Clark]

DC

Thanks for the reply! I'm going to put them on my 75 MX100 (30mm), so bending easy is all relative. 

Hi Jay,

Building a hunnert? Are you going to make a trip south and ride some of the Tripes races with us?

Wendell Clark

[Slakewell]

I thought the forks on YZ A 250 were so good I replaced them with set off a 73 KTM. I did try MX 400B forks for a while which were better. 

[Tahitian_Red]

Hi Wendell,

I've always wanted to come down and try Marty's 100cc Revenge, but I figured I better bring an '82 YZ100 instead of bringing a knife (MX100) to a gun fight.
 


Slakewell,

Were the MX400 fork stronger or did they just have better damping?

[Slakewell]

Mostly better damping and a little less flex ,thou in deep runts you could still have bars at full lock and be going straight ahead. The Ceranies from the KTM were worlds better thou you have to weld and mill the brake lug on the fork , You should also hone the fork leg after welding.