[Easy Rider]

Well this comment might not be that helpful.
WHY do you think that the stock shock needs to be changed to something else ?

 

[Easy Rider]

I feel my rear keep jumping and turn slow , new one ask 400 I want find something cheaper

Not sure I understand "feel my rear keep jumping and turn slow"
but if you really want something better you likely will have to PAY for it.

 

[Easy Rider]

If your "rear is jumping" (assuming I understand you) your rear shock is bottoming out and either does not have enough pre-load (more likely) for your 240lbs or, if you have adjusted

I edited your post so that it looks right.
The comment that you ADD needs to go AFTER the /QUOTE in brackets.