I'm gonna order the SS valve kit with split keepers from OldMiniBikes warehouse. they come with 26# springs. I have dynos CM- grind cam that calls for 22# springs. Should I keep the 26# or replace them with the 22# ??? Its got 26 in it now with stock rockers and retainers. I'm trying to get 7500 rpm out of the little 196cc ducar.
Valve springs
- Thread starter jaxdezi
- Start date
Keep the 26lb springs. Do you have a way to measure seat pressure or installed height? The spring is rates at xxlbs at .xxx height. There are two types of keepers that can change the installed height a mid groove and high groove. But usually if you are just taking what you get it will be midgroove and the installed height will be around .850. The 26lb springs are approximately 26lbs seat pressure at .848. If your installed height is greater the spring pressure will be less.
Its tav. I had it on mb165 w/7" driven, blue driver springs, zinc weights 9t/72t sprockets, 18.25" tire. It would spin to 6600. Now its on grandsons go kart w/ 6" driven, 15" tires, 9t/60t sprockets. It spins to 5400. I got blue and white driver springs, alum. weights ordered. Gotta get another 7" driven too. I know the stock size carb is limiting it, but I want it bullet proof before I go to a bigger carb.
