I Put a yellow main spring in my kids buggy a while back and it was a great improvement however I notice the clutch was not looking great chunks of the pads were missing and some cracks in others. I put it on the ill get to it list. Well took the kids up a mountain on a logging road and on the way back down we coasted the engine stalled in drive and long story short the belt was destroyed. after kicking myself a few times for the stupid move. I decided it was time to rebuild the whole darn trans on the buggy. I ordered a kevlar belt a performance clutch with yellow springs, new case gasket, and some new 10 gram rollers as they seem to be the favorite among folks on this site. the clutch i got was this
http://www.ebay.com/itm/191938328196 when it arrived the yellow springs were not installed there were blue ones installed on the clutch assembly. I decided I would give the blue springs a shot since it was extremely hot out and I did not feel like tearing the clutch apart. I reassembled everything and tried it out. I was amazed at how well the buggy drove it used to surge to get going now it drives smooth like a real car. also has good power going up the steep trails on my property. I spent about 65 to 70 bucks on all the parts but it is amazing how much better the machine drives. My suggestion do not overlook the clutch! I know I cheaped out and used ebay stuff but the results were good for me and better for my budget. BTW if your gonna tackle the job go buy yourself a 1.5 inch impact socket for removing the clutch nut it will save you lots of headaches.