When I shift into reverse or forward is it normal for a jittering noise and movement inside the clutch housing that you can feel. This is my first 400 Sport and I'm wondering if this is normal. Its a '97 400 Sport with a green spring .020 Weisco, V-Force, Ported, DG pipe (1st year offered), K&N, lightened flywheel. As many of you may of read this is my first Polaris. Bought it used. What should I look for (potential Polaris problems). Thank you for your replies in advance.

'97 405 Sport
'99 435EX

 

Did you inspect the belt when you installed the green spring?Sounds belt related to me,
Bill

 

It likely is either a belt going south, or your idle speed is set too fast. Did it do this before the spring change? If not, maybe the outer clutch housing (the part of the pulley you remove when changing the spring) got turned, throwing the balance off. Hope this helps.
Farmr