Viper engagement rpm to high

[jonlafon1]

Have a buddy with 17 viper with everything stock. Looking to LOWER engagement rpm to 2900. I'm on the Sidewinder side of things and never had Yamaha clutches that are on the vipers. Simple as a different primary spring is what I'm thinking. He does not want to do a whole clutch kit. The stock spring seems like it would be soft enough looking at the Yamaha spring chart. BUT it's engaging around 3600. Thanks for any ideas.
Jon

 

[DranttelSS]

BOP soft start spring

 

[SHARPMACHINE]

http://www.barnofparts.com/soft-start-clutching

 

[jonlafon1]

Thanks guys! Just what we're looking for!

 

[grizztracks]

I tried changing out just the spring to lower engagement on my Viper but now run Schmidt Bros low engagement spring and small roller combination. The Schmidt bros setup (comfort clutch) works much better than just replacing the spring alone. Reduced roller diameter is the key if you want to do it right.

 

[Redbeard]

Reduced roller diameter is the key if you want to do it right.

What diameter roller did you switch to?

 

[grizztracks]

What diameter roller did you switch to?

Schmidt's are custom made and If I remember right they are 14.7 mm. I ran them in my Nytro for years and they worked well. When I got the Viper I decided to try a few different setups without the smaller rollers but finally went back to them.