rx1 Belt sliping under boost

[925rotax]

05 rx1 running 18-22 pds boost, the belt wants to slip about half throttle so i back out and get on it again. The belt only slips under load in a climb , not racing across a flat area.Sheaves are good and scuffed clean and replaced secoundary, tried several belts,shoiuld i tighten the secoundary up more to bring sheaves together. Top of belt sits flush on top of secoundary sheave, seems to be slipping on primary due to some belt wear at bottom of sheaves, but no rubber on mid to top of primary or secoundary sheaves?

 

[mbarryracing]

Need a stronger secondary spring and more weight to grab the belt harder.

 

[Skydog]

Yes try a Sliver

 

[925rotax]

thanks guys!

 

[Skydog]

Yea buddy that was silver 2ndary yamaha spring.