This is a Broken-in replacement piston/sleeve/rod
replacement for Ultimate Racing M5S or the OS B2103 type R.
This Piston/Sleeve/Rod is bench broken-in using the heat cycle method
using our special break-in fuel. This
Piston/Sleeve/Rod has then had 250cc of the 30/8 blend of fuel ran through it
as well. This replacement
Piston/Sleeve/Rod allows you to rebuild the Ultimate Racing M5S or the OS B2103 type R with a
drop in broken-in Piston/Sleeve/Rod. We
recommend running 2 rich setting tanks of fuel through your vehicle before you
put that race tune on it.