Looking to lower engagement RPM

[TCviper22]

I have 02 Viper 700 improver that I'm looking to lower the engagement for snow drags. It has an engagement of 4500 currently for Ice drags. Has a orange primary spring that I believe is 55/135 and one shim I believe. I would like the new engagement to be somewhere around 3800 or less. I'm currently debating getting adjustable weights.

Thanks guys
Jimmy

 

[mrviper700]

buy a yamaha green-white-green primary spring and remove the shim, should be perfect and still keep your topend rpm the same.