I've a 87 250x. I've been racing it on the short track, I've been wanting to mx it. I've already got a killer engine and a great set of double rate front works shocks. I was wanting to know if the a-arms off of a 400ex would set the front of my atv at the right height to mx. I was also wondering what other parts off of a 400ex are compatable with my 250x.


thanks for any help ya'll can be.

 

yes, the 400ex arms will work on the 300ex.
the 250r's arms will work also.
(you will need to chave alittle off the bushings with the 250r arms)

i have the 400ex arms and shocks on my 300ex. my bike is wider than a stock 400ex in the front.
you will either need to use aftermarket shocks set up for +2 arms, or use the 400ex shocks. (250r shocks will work too), BUT you will need to fabricate another upper shock mount to account for the longer shocks. if you use the stock 33ex shocks, it'll look cool, but will bottom out on jumps.
your works shocks set up for stock 300ex arms will not work either. (i do not think)
if you decide to use aftermarket shocks, be sure and tell them that your useing the 400ex or 250r arms. (makes a differance {lower shock mount)

this mod will not make your bike any "highter" unless you don't make another top shock mount. 400ex shocks are about 2 1/2 or 3 inches longer. i think the 300ex sits at 9 1/2 at the front rear lower arm. + 3 inches...11" of clearance (not good)

other parts
...400ex carb....
...350x swingarm (+1 1/4) must use 350x rear shock, or aftermarket for 350x swingarm)
......................350x uses a linkage....300ex doesn't
......................also you need to put in a few spacers between the swingarm and the frame the 350x swingarm is about 1/2 inch narrower than the 300ex, (use washers')
...350x motor (modify 400ex head pipe) use 400ex slip on.
...350x air boot (match to 400ex carb)

the 300ex is a pretty cheeply modded bike.....after putting on the 400ex arms, it handles WAY better...soaks up dozer rutts like crazy...and you can use the stock 300ex brake lines. and spindles. all you need is arms, tie-rods and shocks from a 400ex.

...hope i helped....
.ask away...

 

I did the 250R a-arm conversion, I'm running works shocks that are made for stock a-arm lengeth and it works fine just rides low. Check out my photo gallery for pics of it