DT125R FORUM

@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).

Cheers @beng1968 . I must admit, I bought 2 more Athena kits sometime after this post was made and can't concur with the opinions here. The casting was spot on and it was very good value for money. Considering it comes with everything you'd need to bolt it onto your engine, I'd say it's good value. I will agree it's not YZ rip roaring performance from stock, and considering the extent of tuning on my DTR, it's still nothing compared to a stock Aprilia RS 125. However, it's not without its merits. The extra CCs give a nice broader range of power, which as I've gotten older I've come to appreciate more (I'm no longer 75kgs wet ). I did take my cylinder to Mick Abbey for further porting and there is still more porting work that I need to do on my setup. It should be a decent bit of kit, when setup properly. The first experience I had was when I loaned my brothers 2001 DTR back in 2010, he'd fitted the Athena kit amongst various other mods, and that went very well. At the time, I went all in on a ported 3MB00P cylinder from the TZR Belgarda and that setup definitely served me well. I haven't been on my DTR for several years now and I am eager to fire it up again to rejudge my opinion.