There seems to be a good deal of knowledge in here with 250/350X's.

I have a '91 250X that had a 350X rear shock installed when I bought it. The bottom mount on the 250X swingarm was cut off and new one welded on and the top hole in the shock was drilled to accept the 250X bolt. That's the setup, now...

I rode and liked it fine for 3 years. One day on a 3' jump I snapped the shock rod right above the threads that screw into the bottom mount.

Every place I called said no parts available, buy a new shock. Tight on money and liking the ride, I bought a complete USED 350X unit. It worked fine for over a year. You guessed it. Broke it the same way doing roughly the same thing.
Now I wondered if something was wrong with the setup or if I buying a USED shock was the culprit.
I considered buying WORKS or something but the cheapest aftermarket had no adjustments and was the same price ($400) as a new Honda part.
A new Honda shock would last and Honda are great quality I reasoned.

Well, I rode just 3 times in 2 months and mother f&%#er if it didn't break the same way. I now have 3 shocks lying around as junk. Very annoying.
The Honda dealer almost laughed when I asked about warranty on off road parts. (I wondered how he would look with the spring wound around his neck the *******).

This long story leads to a question...does anyone know where to get internal parts for the 350X shock or someone who can rebuild them?
Next time I bolt it on I'll do my homework with the alignment first.
Has this happened to any 350X owners?
I'm mistified because the first 2 shocks lasted through quite a bit of riding.

Yella Terra

'00 DS650, '91 250X, '87 250X, '85 FL350R

 

you should have changed swings arms also the 350x swing arm is 2" longer that the 250x so therefore the shock is set up to have a +2 250x swinga arm i would think that the 350x shock is too long and not set up right to use a 250x stock swing arm

 

One thing you should check the shock movement throughout the complete shock travel. I would suspect that it is binding or bottoming too hard when it is compressed. You may need to move the mounting position on the swingarm. As far as anyone that can do a rebuild. Works, Legacy, PEP, TCS, These companies should be able to help you out. I know for the 250r shocks they do a heart transplant for around $300-$400. I am mounting a 250R swingarm and shock to mine.

 

If you bought a complete 350x, why not put the whole rear end on and a much better ride. The swing arm is about 1 1/2 inch longer and the axle is wider. I did this on my 87 250x and it made a big difference in the ride.
Back to you shock breaking, I would guess that the thing is not lined up correctly and it is binding.

many 250r's
87 250x
99 400ex