DT125R FORUM

@Calum Sorry to hear about your car bud. +1 for I'd keep hold of those extra clutch cover inserts if I were you, they look ace and are a part that can get rubbed/scratched just from riding so it would be cool to be able to just bung on a fresh one as and when.

@calum said in Athena 170 porting:

@lllDennis I read that the port timings were off by 3mm because apparently the barrel was based off a dtr200. How true that is...

Would love to see before and after dyno pulls though. See how the stock Athena compares to a modified one.

I have compared Athena 170 kit vs 3MB P (and 2RH) cylinders, the only 2 things that's off the athena kit is the piston taller than the stock,the ports are exact copy off the 3MB just a bit wider and the c port is little lower and matches more a 2RH cylinder

The 170 is a mix between the 200cc casing (for the cooling canals and ypvs location) and 125 portmap internally.I searched for a piston that has the dimensions of the 56mm and with bore of 65mm but there is not,only some aftermarket forged that are max 61mm have the right piston height (pin to top).