Originally Posted by Jumpa
Just remember the piston Battle I believe you need the flying horse or the Skyhawk piston as these two motors have the longer connecting rods
His motor does not have a longer connecting rod.
The 40 mm stroke is 2 mm more than a 38 mm stroke motor because the lower connecting rod pin is drilled 1mm closer to the outside.
His motor needs a PK style piston with the lower wrist pin hole.
A Skyhawk / GT 5 piston has the higher hole.
Who knows what a Flying Horse motor really is as some vendors call any and all of their motors by that brand name.