it just seem like the shaft is bigger idk. i will look into it more. something else i see to day. the duratrax .18 and .16 motor looks the same the rod is the same is it just the bore size or would it effect everything like how the head fits and all. would like to get my st back up a running. even if its a bit slower.
i had a nitro evader. after may pistons and sleeves in the duratrax motor i bought an o.s. .15 . it dropped right on with no mods at all. you might want to ditch the stock duratrax pipe for an associated pipe. the duratrax pipe has a baffle that can come loose in a crash and mess up the tune of the motor causing a lean condition ruining the piston and sleeve. the stock duratrax clutch will bolt right on this motor