hi all just a little question about the athena 170 piston kit for the dtr e 125. i cant quite get my head around how the cylinder bolts on to the crankcase. i would imagine that the cylinder should have a larger diameter hence 170cc and on the net the pictures show the kit comes with its own studs why take the old studs out has anyone else fitted these before and would it but the crank bearings and the rest of the bottom end components under too much strain? thanks every one

Are you sure the studs aren't barrel to head and exhaust?

Fitting holes for the cranks are clearly shown here

hi all just a little question about the athena 170 piston kit for the dtr e 125. i cant quite get my head around how the cylinder bolts on to the crankcase. i would imagine that the cylinder should have a larger diameter hence 170cc and on the net the pictures show the kit comes with its own studs why take the old studs out has anyone else fitted these before and would it but the crank bearings and the rest of the bottom end components under too much strain? thanks every one

They are fir the head and exhaust. The bore only increaces by 6mm the power comes from the port size and shape and a better powervalve.

And yes it most definately will load the crank up and the rest of the bike. Doubling the hp will ramp up the stress. You cannot expect it to do twice the work without twice the maintainance.

thanks for the the picture dirtydt. if you look at the object between the head and the power valve it looks to me to be a flywheel, and if it is it is the wrong type for the dtr. i guess it will be left out?

thanks cynic If memory serves the very first model dt1 came out the same time as the xt 500 and was a 175 until the the british government brought out the CBT 125 cc law. yamaha responded by bringing out the dtr 125. i wonder if they simply put a 125cc top end onto the existing 175 bottom end?