Description
The ProX Piston Kit for Yamaha 760/1200 1.50 mm oversize is one of the largest common overbore options for these engines, aimed at cylinders with significant wear or prior damage. At this size, careful evaluation of cylinder wall thickness and casting condition is essential before machining. When the base material is sound, this kit can give a heavily used ski a valuable new lease on life.
- 1.50 mm oversize piston kit for Yamaha 760 and 1200 engines that require aggressive cylinder cleanup.
- Supplied with oversize piston, ring set, wrist pin, and circlips to fully renew the piston group on one cylinder.
- Manufactured from the familiar low expansion, low friction alloy used across the ProX two stroke piston line.
- Machined on modern CNC equipment for accurate skirt profile, crown shape, and ring groove geometry.
- Best suited to experienced builders and riders committed to extending the service life of older machines.
With proper boring and honing, this large oversize can bring back compression and ring sealing that felt out of reach with smaller steps. Engines that once struggled to plane can again pull strongly through the mid range and carry speed in rough water. When matched to healthy ignition, fuel, and cooling systems, the ProX 1.50 mm piston supports dependable operation despite the demanding overbore.
Because this is a deeper cut, builders should sonic check or otherwise verify wall thickness where possible, and thoroughly inspect crankcases, crankshaft, and bearings. Use quality gaskets, confirm squish clearance, and follow torque and break in recommendations closely. Treated with respect, the ProX 1.50 mm oversize kit can keep Yamaha 760/1200 powered skis in the rotation rather than on the scrap pile.
