High Compression Piston

I am new to the forum and this is my first post. I have a 2012 KX250F and will be doing some motor work in the near future. My goal is to increase the low end grunt without sacraficing reliability. Furthermore, i am an intermediate level rider and dont want to go "overboard" and create an un-rideable beast. I have previously installed a PC Ti-5 exhaust system. My plan is to do some head work and to remove the air cleaner screen. I am considering a high compression piston but wanted to get some feedback about expected increases in power. The stock compression ratio is 13.5:1 and a typical high compression piston (Pro Circuit, for example) will increase this by one point. Also, if i do go ahead and install the high compression piston, is it recommended to replace/upgrade other internal components such as wrist pin, springs, valve seats, etc. Thank you

Typically if you go with an aftermarket high compression piston it will come with the appropriate rings, pin, and retainers. Cosworth makes a good high compression piston for the Kawi's. You dont need to upgrade the valve springs when doing a high compression piston but you will need to run at minimum a mix 50/50 of race gas depending on what compression you go up to. You would be better off getting a performance cam over a high compression piston though dollar for dollar wise.

some say fitting a high comp piston can lead to putting excess pressure on the big end (and i tend to believe them), i would check into this before you went ahead and fitted one.

13.5:1 is about as high as I would go on pump gas. Any more and i'd be mixing race gas with pump, and then its like whats the point of mixing good race gas with the ethanol junk and end up just running race fuel. Put a set of stage 1 cams in it for low end and get it re mapped for the power to be tailored to your liking. For somebody not going overboard suprised you spent the extra 500 dollars for the TI over stainless exhaust....

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now