Predator 212 Hemi Valve spring size

[MinibikeBoy123]

Hi, I have a Predator 212 Hemi and at high rpm's it gets valve float. I need to know the strength valvle springs I should by for it. I curently have stage 1 gopowersports engine kit with header pipe but will be upgrading to mikuni. What strength valve springs do you recommend? Thanks!

 

[DeadPixel]

If keeping the stock cam than 18# springs but don't get the 22mm carb or replace the springs tell you replace your rod and flywheel or it wont last long. You need at least a billet rod as it is right now. Take it easy tell you replace the rod and don't put new springs tell you replace the flywheel.

 

[CarPlayLB]

Like what DeadPixel said. The stock valve springs are helping to keep your engine alive right now! The stock rod and flywheel are the weak links. The valve float is keeping the rpm's down!
The stock rod does not like rpm's over 5000. It will starve for oil and slowly weld itself to the crank...shortly after that it will kick out the front of the case. The magnet on the stock flywheel can come off at higher rpm's and take out the coil and the block...that is if the flywheel does not explode first! Please be safe!
The standard Honda 18# springs will not work on the Hemi engine. Too many coils combined with a shallow spring pocket will give you a coil bind situation. The next step is the 22# springs
https://www.OldMiniBikes.com/2-pack-of-22lb-valve-springs.html

To run the 22mm Mikuni (Chikuni), you really need a bigger cam with the billet rod and flywheel. Do it right, do it once, be safe and have fun!