I am instaling a 12.5 piston and just wondering if I need a hotter plug and any jetting with it as well? thanks

 

keep same jetting, lighten the fly wheel it really makes a big different. its only 100 bucks and you will be beating up on yfzs

 

yea just got my flywheel back had it lightend and also added 2.5 inches to my swingarm I hope it rips!

 

i was thinking on going with 12.5 piston, do you need stronger springs, vavles, or buckets? thanks for any imput.

 

You dont need stronger springs unless you get a rev box that has no rev limit. I sold my predator and tried to buy it back the next day. Anyway i had the vortex cdi from hpd on mine, it would rev all the way to 10001. I have a dsx now and have put a cdi box from procom on it and my new ds will not outrun my 03 predator cause i have allready tried it. my predator had lighten fly wheel, stronger spings, 12.5 piston, hpd race pipe, rath hill gards. vortex cdi,