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ProX Piston 2T


With over 35 years of experience in piston production! Pistons from ProX are the obvious choice when it's time for piston replacement

ProX is one of the worlds largest manufacturers of racing pistons. They have been providing the racing community with great quality, affordable pistons since 1975. ProX pistons are jsut like your original piston, but at a much lower price.

The Pistons are made from Aerospace aluminium and CNC machined from one piece for optimal shape and longevity.

All pistons come with piston rings, piston pins and clips of the best quality

Choosing your piston:
B-size pistons are recommended for all used cylinders.

A-size pistons are for new cylinders only.

A B-size piston is one hundredth of a millimetre larger than an A-size piston, in order to compensate for wear. C-size piston is larger than B-size piston etc..

When changing the Piston:
If the old piston is defective, find out why and correct the error asap. Common causes of piston failure include wrong fuel mixture, too low heat in your spark plugs, faulty ignition setting or an air leakage.

If the old piston has fragmented or completely burned through, remove the crank case and carefully clean the metal debris.

Check the cylinder for wear.

When installing the piston always replace old gaskets with new ones!

The piston is mounted with the arrow pointing towards the exhaust side. Piston pin lock rings are placed carefully with lock slot down.

Install the piston rings on the piston. Be aware that some pistons are equipped with keystone piston rings. These are tapered and can easily be positioned incorrectly. Make sure the piston ring is completely in the ring groove and the ring gap closes. Lubricate all parts with engine oil 10W30 or 10W40.

Place a new cylinder base gasket onto the crankcase, compressing the piston rings and gently sliding down the cylinder into position. Before installing the cylinder head ensure the crankshaft is rotated by hand and check that the piston rings move freely within the cylinder.

New pistons require some breaking in: Adjust the carburettor to a slightly richer fuel mixture. Avoid riding at extremely high or low speed, vary the riding speed and do not accelerate at full throttle. After an engine inspection additional oil should be added to the fuel.

Pistons are manufactured in great numbers and the material is just a very, very small part of production costs. This means that no manufacturers will choose poor materials. If a new piston brakes down, it is not going to be because of the piston! Common mistakes can be that the piston has been mounted in an unevenly worn cylinder, faulty mounted piston rings, faulty carburettor settings, improper fuel mixture, or other damage to the connecting rod / crankshaft.